High metathesis activity ruthenium and osmium metal carbene complexes

ABSTRACT

Ruthenium and osmium carbene compounds that are stable in the presence of a variety of functional groups and can be used to catalyze olefin metathesis reactions on unstrained cyclic and acyclic olefins are disclosed. Also disclosed are methods of making the carbene compounds. The carbene compounds are of the formula 
                         
where M is Os or Ru; R 1  is hydrogen; R is selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted aryl; X and X 1  are independently selected from any anionic ligand; and L and L 1  are independently selected from any neutral electron donor. The ruthenium and osmium carbene compounds of the present invention may be synthesized using diazo compounds, by neutral electron donor ligand exchange, by cross metathesis, using acetylene, using cumulated olefins, and in a one-pot method using diazo compounds and neutral electron donors. The ruthenium and osmium carbene compounds of the present invention may be used to catalyze olefin metathesis reactions including, but not limited to, ROMP, RCM, depolymerization of unsaturated polymers, synthesis of telechelic polymers, and olefin synthesis.

This application is a continuation of U.S. patent application Ser. No.11/929,212, filed Oct. 30, 2007, now abandoned, which is a divisionalapplication of U.S. patent application Ser. No. 11/472,137, filed Jun.20, 2006, now U.S. Pat. No. 7,288,666, which is a divisional applicationof U.S. patent application Ser. No. 10/968,361, filed Oct. 18, 2004, nowU.S. Pat. No. 7,102,047, which is a divisional application of U.S.patent application Ser. No. 10/325,998, filed Dec. 19, 2002, now U.S.Pat. No. 6,806,325, which is a divisional application of U.S. patentapplication Ser. No. 09/746,146, filed Dec. 21, 2000, now U.S. Pat. No.6,515,084, which is a divisional application of U.S. patent applicationSer. No. 09/399,963, filed Sep. 20, 1999, now U.S. Pat. No. 6,211,391,which is a divisional application of U.S. patent application Ser. No.09/007,498, filed Jan. 15, 1998, now U.S. Pat. No. 6,111,121, which is adivisional application of U.S. patent application Ser. No. 08/693,789,filed Jul. 31, 1996, now U.S. Pat. No. 5,831,108, which claims thebenefit of U.S. Provisional application No. 60/001,862, filed Aug. 3,1995, and U.S. Provisional application No. 60/003,973, filed Sep. 19,1995, all of which are incorporated herein by reference.

The U.S. Government has certain rights in this invention pursuant toGrant No. CHE-8922072 awarded by the National Science Foundation.

BACKGROUND

This invention relates to highly active and stable ruthenium and osmiummetal carbene complex compounds, their synthesis and use as catalystsfor olefin metathesis reactions.

Transition-metal catalyzed C—C bond formation via olefin metathesis isof considerable interest and synthetic utility. Initial studies in thisarea were based on catalytically active mixtures consisting oftransition-metal chlorides, oxides or oxychlorides, cocatalysts such asEtAlCl₂ or R₄Sn, and promoters including O₂, EtOH or PhOH. For example,WCl₆/EtAlCl₂/EtOH 1:4:1. These systems catalyze olefin metathesisreactions, however their catalytic centers are ill-defined andsystematic control of their catalytic activity is not possible.

Recent efforts have been directed towards the development ofwell-defined metathesis active catalysts based on transition metalcomplexes. The results of research efforts during the past two decadeshave enabled an in-depth understanding of the olefin metathesis reactionas catalyzed by early transition metal complexes. In contrast, thenature of the intermediates and the reaction mechanism for Group VIIItransition metal catalysts have remained elusive. In particular, theoxidation states and ligation of the ruthenium and osmium metathesisintermediates are not known.

Group VIII transition metal olefin metathesis catalysts, specificallyruthenium and osmium carbene complexes, have been described in U.S. Pat.Nos. 5,312,940 and 5,342,909 and U.S. patent application Ser. Nos.08/282,826 and 08/282,827, all of which are incorporated herein byreference. The ruthenium and osmium carbene complexes disclosed in thesepatents and applications are of the general formula

where M is ruthenium or osmium, X and X′ are anionic ligands, and LandL′ are neutral electron donors.

U.S. Pat. Nos. 5,312,940 and 5,342,909 disclose specific vinylalkylidene ruthenium and osmium complexes and their use in catalyzingthe ring opening metathesis polymerization (“ROMP”) of strained olefins.In all of the specific alkylidene complexes disclosed in these patents,R¹ is hydrogen and R is either a substituted or unsubstituted vinylgroup. For example, a preferred vinyl alkylidene complex disclosed inthese patents is

where Ph is phenyl.

U.S. patent application Ser. Nos. 08/282,826 and 08/282,827 disclosespecific vinyl alkylidene ruthenium and osmium complexes and their usein catalyzing a variety of metathesis reactions. The catalysts disclosedin these applications have specific neutral electron donor ligands L andL¹; namely, phosphines in which at least one substituent is asecondary-alkyl or cycloalkyl group. As in the above U.S. patents, inall of the specific alkylidene complexes disclosed in the patentapplications, R′ is hydrogen and R is either a substituted orunsubstituted vinyl group. For example, a preferred vinyl alkylidenecomplex disclosed in these patent applications is

where Cy is cyclohexyl.

Although the vinyl alkylidene complexes disclosed in the above patentsand patent applications exhibit high metathesis activity and remarkablestability towards functional groups there are at least two drawbacks tothese complexes as metathesis catalysts. First, the preparation of thevinyl alkylidene complexes requires a multi-step synthesis; and second,the vinyl alkylidene complexes have relatively low initiation rates.Both of these aspects of the vinyl alkylidene complexes are undesirablefor their use as metathesis catalysts. The multi-step synthesis may betime consuming and expensive and may result in lower product yields. Thelow initiation rate may result in ROMP polymers with a broad molecularweight distribution and prolonged reaction times in ring closingmetathesis (“RCM”) reactions.

For the reasons discussed above, there is a need for well-definedmetathesis active catalysts that have the following characteristics:first, they are stable in the presence of a wide variety of functionalgroups; second, they can catalyze a variety of metathesis reactionsincluding the metathesis of acyclic and unstrained cyclic olefins;third, they have a high initiation rate; and fourth, they are easilyprepared. Furthermore, there is a need for olefin metathesis catalyststhat can catalyze the ROMP of strained and unstrained cyclic olefins toyield polymers of very low polydispersity (i.e., POI=1.0) and that cancatalyze the RCM of acyclic dienes with short reaction times.

SUMMARY

The present invention meets the above needs and provides well-definedruthenium and osmium carbene compounds that are stable in the presenceof a variety of functional groups and can be used to catalyze olefinmetathesis reactions on unstrained cyclic and acyclic olefins. Thecompounds of the present invention are highly active in metathesisreactions and have high initiation rates.

In one embodiment of the present invention, the ruthenium and osmiumcarbene compounds have the formula

where M may be Os or Ru; R¹ is hydrogen; X and X¹ may be different orthe same and are any anionic ligand; L and L¹ may be different or thesame and are any neutral electron donor; and R may be hydrogen,substituted or unsubstituted alkyl, or substituted or unsubstitutedaryl.

The ruthenium and osmium carbene complexes of the present invention arestable in the presence of a variety of functional groups. A consequenceof this is that the alkyl and aryl R group may contain one or morefunctional groups including alcohol, thiol, ketone, aldehyde, ester,ether, amine, imine, amide, nitro, carboxylic acid, disulfide,carbonate, isocyanate, carbodiimide, carboalkoxy, and halogen groups.

R is preferably hydrogen, C₁-C₂₀ alkyl, or aryl. The C₁-C₂₀ alkyl mayoptionally be substituted with one or more aryl, halide, hydroxy, C₁-C₂₀alkoxy, or C₂-C₂₀ alkoxycarbonyl groups. The aryl may optionally besubstituted with one or more C₁-C₂₀ alkyl, aryl, hydroxyl, C₁-C₅ alkoxy,amino, nitro, or halide groups.

L and L¹ are preferably phosphines of the formula PR³R⁴R⁵, where R³ is asecondary alkyl or cycloalkyl, and R₄ and R₅ are aryl, C₁-C₁₀ primaryalkyl, secondary alkyl, or cycloalkyl. R⁴ and R⁵ may be the same ordifferent.

L and L¹ are are most preferably the same and —P(cyclohexyl)³,—P(cyclopentyl)³, or —P(isopropyl)³.

X and X¹ are most preferably the same and are chlorine.

In another embodiment of the present invention, the ruthenium and osmiumcarbene compounds have the formula

where M may be Os or Ru; X and X¹ may be different or the same and areany anionic ligand; L and L¹ may be different or the same and are anyneutral electron donor; and R⁹ and R¹⁰ may be different or the same andmay be hydrogen, substituted or unsubstituted alkyl, or substituted orunsubstituted aryl. The R⁹ and R¹⁰ groups may optionally include one ormore of the following functional groups: alcohol, thiol, ketone,aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid,disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, and halogengroups

The ruthenium and osmium carbene compounds of the present invention maybe used to catalyze olefin metathesis reactions including, but notlimited to, ROMP, RCM, depolymerization of unsaturated polymers,synthesis of telechelic polymers, and olefin synthesis.

In the ROMP reaction, a compound according to the present invention iscontacted with a cyclic olefin to yield a ROMP polymer product. In theRCM reaction, a compound according to the present invention is contactedwith a diene to yield a ring-closed product. In the depolymerizationreaction, a compound according to the present invention is contactedwith an unsaturated polymer in the presence of an acyclic olefin toyield a depolymerized product. In the synthesis of telechelic polymers,a compound according to the present invention is contacted with a cyclicolefin in the presence of an α,ω-difunctional olefin to yield atelechelic polymer. In the olefin synthesis reaction, a compoundaccording to the present invention is contacted with one or two acyclicolefins to yield self-metathesis or cross-metathesis olefin products.

Since the ruthenium and osmium carbene compounds of the presentinvention are stable in the presence of a variety of functional groups,the olefins involved in the above reactions may optionally besubstituted with one or more functional groups including alcohol thiol,ketone, aldehyde, ester, ether, amine, imine, amide, nitro, carboxylicacid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, andhalogen groups.

The above reactions may be carried out in aqueous, protic, or organicsolvents or mixtures of such solvents. The reactions may also be carriedout in the absence of a solvent. The reactants may be in the gas phaseor liquid phase.

The ruthenium and osmium carbene compounds of the present invention maybe synthesized using diazo compounds by neutral electron donor ligandexchange, by cross metathesis, using acetylene, using cumulated olefins,and in a one-pot method using diazo compounds and neutral electrondonors.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by reference to the appendedfigures wherein:

FIGS. 1A and 1B are representative kinetic plots for acyclic metathesisof 1-hexene with RuCl₂(═CHPh)(PCy₃)₂ (complex 10) at 0° C.; and

FIG. 2 is an ORTEP plot of RuCl₂(═CH-p-C₆H₄Cl)(PCy₃)₂ (complex 15).

DETAILED DESCRIPTION OF THE INVENTION

The abbreviations Me, Ph, ^(i)Pr or i-Pr, Cy, Cp, n-Bu, and THF refer tomethyl, phenyl, isopropyl, cyclohexyl, cyclopentyl, n-butyl, andtetrahydrofuran, respectively.

While previous investigations have explored the influence of the neutralelectron donor and anionic ligands (i.e. L, L¹, X, and X¹) on thestability and utility of the ruthenium and osmium carbene complexes, theeffect of variation of the alkylidene moieties (R and R¹) had not beenstudied. By studying the effect of these substituents, it has beendiscovered that ruthenium and osmium complexes containing the specificalkylidene moieties of the present invention have unexpectedly highinitiation rates compared to the vinyl alkylidene complexes previouslydescribed. Quantitative data is included below that demonstrates thatthe initiation rates of the complexes of the present invention areapproximately a thousand times higher than the initiation rates of thecorresponding vinyl alkylidene complexes. In addition to havingunexpectedly high initiation rates, the complexes of the presentinvention are stable in the presence of a variety of functional groupsand have high metathesis activity allowing them to catalyze a variety ofmetathesis reactions including metathesis reactions involving acyclicand unstrained cyclic olefins.

The compounds of the present invention are ruthenium and osmiumalkylidene complexes of the general formula

where R¹ is hydrogen and R is selected from the specific group describedbelow. Generally X and X¹ can be any anionic ligand and L and L¹ can beany neutral electron donor. Specific embodiments of X, X¹, L, and L¹ aredescribed in detail in U.S. Pat. Nos. 5,312,940 and 5,342,909 and U.S.patent application Ser. Nos. 08/282,826 and 08/282,827.

R may be hydrogen, substituted or unsubstituted alkyl, or substituted orunsubstituted aryl. The ruthenium and osmium carbene complexes of thepresent invention are stable in the presence of a variety of functionalgroups. A consequence of this is that the alkyl and aryl R groups maycontain a variety of functional groups including alcohol, thiol, ketone,aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid,disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, and halogengroups.

In a preferred embodiment R is hydrogen, C₁-C₂₀ alkyl, or aryl. TheC₁-C₂₀ alkyl may optionally be substituted with one or more aryl,halide, hydroxy, C₁-C₂₀ alkoxy, or C₂-C₂₀ alkoxycarbonyl groups. Thearyl may optionally be substituted with one or more C₁-C₂₀ alkyl, aryl,hydroxyl, C₁-C₅ alkoxy, amino, nitro, or halide groups. In a morepreferred embodiment, R is hydrogen, C₁-C₄ alkyl, phenyl, C₁-C₄ alkylsubstituted with one or more groups selected from the group consistingof halide, hydroxy, and C₂-C₆ alkoxycarbonyl, or phenyl substituted withone or more groups selected from the group consisting of C₁-C₅ alkyl,C₁-C₅ alkoxy, amino, nitro, and halide.

In a more preferred embodiment R may be hydrogen, methyl, ethyl,n-butyl, iso-propyl, —CH₂Cl, —CH₂CH₂CH₂OH, —CH₂OAc, phenyl. The phenylmay optionally be substituted with a chloride, bromide, iodide,fluoride, —NO₂, —NMe₂, methoxy, or methyl group. In a more preferredembodiment, the phenyl is para-substituted.

In a most preferred embodiment R is phenyl.

Preferred complexes of the present invention include

where R is cyclohexyl, cyclopentyl, iso-propyl, or phenyl.

The most preferred complex of the present invention is

The ruthenium and osmium alkylidene complexes of the present inventionmay be synthesized by a variety of different methods including thosetaught in P. Schwab et al. Angew. Chem. Int. Ed. Engl. 34, 2039-2041(1995), and P. Schwab et al. J. Am. Chem. Soc. 118, 100-110 (1996), bothof which are incorporated herein by reference.

The ruthenium and osmium complexes of the present invention may besynthesized by alkylidene transfer from diazoalkanes. This syntheticmethod may generally be written as

where M, X, X¹, L, L¹, R and R¹ are as described above; m and n areindependently 0-3 such that m+n=3; and p is a positive integer. In thediazo synthesis, a compound of the formula (XX¹ML_(n), L¹ _(m))_(p) iscontacted with a diazo compound of the formula RC(N₂)R¹ to yield analkylidene according to the present invention.

The ruthenium and osmium complexes of the present invention may also besynthesized by neutral electron donor ligand exchange as disclosed inU.S. Pat. Nos. 5,312,940 and 5,342,909 and U.S. patent application Ser.Nos. 08/282,826 and 08/282,827.

The ruthenium and osmium complexes of the present invention may also besynthesized by cross metathesis. This method may generally be written as

where R¹¹ and R¹² may be the same or different and may be hydrogen,substituted or unsubstituted alkyl, or substituted or unsubstitutedaryl.

The ruthenium and osmium complexes of the present invention may also besynthesized using acetylene reactants. This method may generally bewritten as

In the acetylene synthesis, a compound of the formula (XX¹ML_(n)L¹_(m))_(p) is reacted with an acetylene compound of the formula R⁹CCR¹⁰,to yield an alkylidene according to the present invention. R⁹ and R¹⁰may be the same or different and may be hydrogen, substituted orunsubstituted alkyl, or substituted or unsubstituted aryl.

The ruthenium and osmium complexes of the present invention may also besynthesized using cumulated olefins. This method may generally bewritten as

The ruthenium and osmium complexes of the present invention may also besynthesized by a “one pot” method that can generally be written as

In this method, a compound of the formula (XX¹ML_(n)L¹ _(m))_(p) iscontacted with a diazo compound of the formula RC(N₂)R¹ in the presenceof a neutral electron donor L² to yield an alkylidene compound accordingto the present invention.

The catalysts of the present invention are highly active in metathesisreactions and may be used to catalyze a variety of metathesis reactionsincluding, but not limited to, ROMP of strained and unstrained cyclicolefins, RCM of acyclic dienes, self- and cross-metathesis reactionsinvolving at least one acyclic or unstrained cyclic olefin,depolymerization of olefinic polymers, acyclic diene metathesispolymerization (“ADMET”), alkyne polymerization, carbonyl olefination,and preparation of telechelic polymers.

ROMP, RCM, cross metathesis, depolymerization, and telechelic polymerreactions have been described in detail in U.S. patent application Ser.No. 08/282,827. Those skilled in the art can readily identify theappropriate conditions for carrying out these reactions using thecomplexes of the present invention. Any specific differences between thereactions disclosed in patent application Ser. No. 08/282,827 and thoseof the present invention are noted in the detailed descriptions givenbelow.

Alkyne polymerization is described by R. Schlund et al. in J. Am. Chem.Soc. 1989, 111, 8004-8006, and by L. Y. Park et al. in Macromolecules1991, 24 3489-3495, both of which are incorporated herein by reference.Carbonyl olefination is described by K. A. Brown-Wensley et al. in PureAppl. Chem. 1983, 55, 1733-1744, by A. Aguero et al. in J. Chem. Soc.,Chem. Commun. 1986, 531-533, and by G. C. Bazan et al. inOrganometallics 1991, 10, 1062-1067, all of which are incorporatedherein by reference. ADMET is described by K. B. Wagener et al. inMacromolecules 1991, 24, 2649-2657, which is incorporated herein byreference. Those skilled in the art can readily identify the appropriateconditions for carrying out these reactions using the complexes of thepresent invention.

We now describe specific examples of the synthesis and olefin metathesisreactions described above. For clarity, detailed reaction conditions andprocedures are described in the final, “Experimental Procedures”section.

SYNTHESIS OF ALKYLIDENE COMPLEXES

Synthesis of RuCl₂(═CHR)(PPh₃)₂ via Alkylidene Transfer fromDiazoalkanes (Complexes 1-9)

The alkylidene complexes of the present invention may be synthesized bythe reaction of RuCl₂(PPh₃)₃ with alkyl, aryl, and diaryldiazoalkanes.Generally, the synthesis reactions involve a spontaneous N₂ evolution at−78° C., indicating rapid reaction of RuCl₂(PPh₃)₃ with diazoethane,diazopropane or a para-substituted aryldiazoalkane of the formulap-C₆H₄XCHN₂ to give RuCl₂(═CHR)(PPh₃)₂ (R=Me [complex 1], Et [complex2]) and RuCl₂(═CH-p-C₆H₄X)(PPh₃)₂ (X=H [complex 3], NMe₂ [complex 4],OMe [complex 5], Me [complex 6], F [complex 7], Cl [complex 8], NO₂[complex 9]), respectively (eq. 1). However, no reaction was observedwith diphenyldiazomethane or 9-diazofluorene at RT, and reaction withdiazomethane led to a complex mixture of unidentified products.

Complexes 1-9 were isolated in 80-90% yield as green air-stable solids.In all of these reactions, transfer of the alkylidene moiety from thediazo compound to ruthenium was clearly indicated by the characteristicdownfield-resonances of H_(α) and C_(α) of the alkylidene moiety. TableI below lists selected NMR data for complexes 3-9.

TABLE I Complex X H_(α) J_(HP)(HZ) Z_(α) J_(PC)(HZ) 3 H 13.56^(a) 10.2310.12 11.4 4 NMe₂ 18.30 6.1 309.68 11.4 5 OMe 19.38^(a) 8.7 309.20 10.76 Me 19.55^(a) 9.6 309.17 10.9 7 F 19.24 9.0 307.51 11.4 8 Cl 19.27 9.2307.34 10.6 9 NO₂ 19.47 10.8 313.43 11.2 Spectra taken in CD₂Cl₂ (inppm) unless indicated otherwise. ^(a)In C₆D₆ (in ppm).

In analogy to the structurally characterized vinyl alkylideneRuCl₂(═CH—CH═CPh₂)(PPh₃)₂ (Complex A), these resonances appear astriplets due to ³¹P coupling. These spectroscopic data suggest that thephosphines are mutually trans and that the alkylidene unit lies in theP—Ru—P-plane. Additionally, the chemical shifts of H_(α) and C_(α) incomplexes 3-9 are downfield compared to RuCl₂(═CH—CH═CPh₂)(PPh₃)₂(Complex A) (67 H_(α)=17.94, C_(α)<288.9 ppm), possibly attributed tothe relatively reduced conjugation of the alkylidene unit of complexes3-9. This phenomenon might also be responsible for the relativeinstability of complexes 1-9 in solution. These complexes decomposewithin several hours via bimolecular pathways as evidenced by theformation of the corresponding disubstituted olefins RCH═CHR(R=Me, Et,p-C₆H₄X).

Synthesis of RuCl₂(═CH-p-C₆H₄X)(PCy₃)₂ via Phosphine Exchange (Complexes10-16)

To broaden the synthetic utility of the triphenylphosphine catalysts,analogous trialkylphosphine derivatives of complexes 3-9 were preparedby phosphine exchange. Treatment of complexes 3-9 with 2.2 equiv.tricyclohexylphosphine at RT afforded, after work-up,RuCl₂(═CH-p-C₆H₄X)(PCy₃)₂ (X=H [complex 10], NMe2 [complex 11], OMe[complex 12], Me [complex 13], F [complex 14], Cl [complex 15], NO₂[complex 16]), as purple (complex 11 is green) microcrystalline solidsin high yields according to the following reaction:

The fully-characterized compounds were air-stable in the solid state anddid not show any signs of decomposition in solution (CH₂Cl₂ or C₆H₆),even when heated to 60° C. or in presence of alcohols, amines or water.Selected solution NMR data for complexes 10-16 are listed in Table II.As can be seen from this data, in contrast to the PPh₃ complexes 3-9, no³¹P coupling was observed for the H_(α) resonances of complexes 10-16 inthe ¹H NMR. The chemical shifts of these resonances are dependent on theelectronic nature of the X substituent.

TABLE II Complex X H_(α) C_(α) J_(PC)(HZ) 10 H 20.02 294.72 7.6 11 NMe₂18.77 286.13 a 12 OMe 19.48 290.90 a 13 Me 19.80 293.86 8.3 14 F 19.86291.52 8.6 15 Cl 19.98 291.46 8.0 16 NO₂ 20.71 289.07 7.6 Spectra takenin CD₂C1₂ (in ppm). a broad signal

The lack of ³¹P coupling suggests that the alkylidene moiety isperpendicular to the P—Ru—P-plane as in RuCl₂(═CH—CH═CPh₂)(PCy₃)₂(Complex B). Also, the resonance shifts' dependency on the electronicnature of the X substituent suggests a high degree of conjugationbetween the carbene carbon and the aromatic ring of the benzylidenemoiety.

One-Pot Synthesis of RuCl₂(═CHPh)(PR₃)₂ (Complexes 10, 17 and 18)

Due to the relative instability of the intermediate RuCl₂(═CHPh)(PPh₃)₂(complex 3) in solution, RuCl₂(═CHPh)(PCy₃)₂ (complex 10) can besynthesized in 75-80% yield from RuCl₂(PPh₃)₃. However, avoidingisolation of complex 3 and adding tricyclohexylphosphine at ≈−50° C.shortly after RuCl₂(PPh₃)₃ was treated with phenyldiazomethane, complex10 can be obtained in nearly quantitative yield in less than 1 hour in aso-called “one pot synthesis”. The same procedure can also be applied tothe synthesis of more soluble derivatives including RuCl₂(═CHPh)(PR₃)₂where R is Cp (complex 17) or R is ^(i)Pr (complex 18) that exhibitcomparable metathesis activity, according to the following reaction:

Synthesis of Methylidene Complex RuCl₂(═CH₂)(PCy₃)₂ (Complex 19)

Whereas RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (Complex B) reacts with ethylene under100 psi pressure at 50° C. in CD₂Cl₂ within several hours to reach anequilibrium of RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (Complex B) andRuCl₂(═CH₂)(PCy₃)₂ (complex 19) in a ratio of 80:20, benzylideneRuCl₂(═CHPh)PCy₃)₂ (complex 10) is quantitatively converted to themethylidene complex 19 within a few minutes at RT under 14 psi ofethylene (eq. 7).

Complex 19 is isolated as a red-purple, air-stable solid. Apentacoordinate ruthenium center may be inferred from the analytic andspectroscopic data. Methylidene complex 19 is less stable in solutionthan benzylidene complex 10; decomposition is observed after 12 hours insolution (CH₂Cl₂, C₆H₆). The decomposition Fate increases as catalystsolutions are heated. Among all isolated methylidene complexes includingRuCl(NO)(CH₂)(PPh₃)₂ and Ir=CH₂(N(SiMe₂-CH₂PPh₂ (₂), complex 19 is thefirst isolable metathesis-active methylidene complex. Complex 19 has ahigh activity and exhibits a similar stability towards functional groupsas benzylidene complex 10, as shown in the ROMP of cyclooctene and1,5-cyclooctadiene and in ring-closing metathesis of diethyldiallylmalonate.

Synthesis of Substituted Alkylidene Complexes via Cross Metathesis

The rapid reaction of RuCl₂(═CHPh)(PCy₃)₂ (complex 10) with ethylene togive RuCl₂(═CHPh)(PCy₃)₂ (complex 19) has prompted extension by theinventors of these metathesis studies to terminal and disubstitutedolefins. Although olefin metathesis is an equilibrium process, thekinetic products may be isolated under certain conditions. Indeed,complex 10 is quantitatively converted to the alkylidenes according tothe formula RuCl₂(═CHR)(PCy₃)₂ [R=Me (complex 20), R=Et (complex 21),R=n-Bu (complex 22)] when reacted with a tenfold excess of propene,1-butene or 1-hexene, respectively. In each case, an equimolar amount ofstyrene was formed and spectroscopically identified (eq. 4).

The isolated compounds 20-22 are comparable to precursor complex 10 instability and solubility and reconvert to precursor complex 10 in thepresence of a large excess (30-50 equiv.) of styrene. Metathesis ofdisubstituted olefins cis-2-butene and cis-3-hexene leads to theformation of RuCl₂(═CHR)(PCy₃)₂ from benzylidene complex 10. However,due to the steric bulk of these olefins, the reactions proceedconsiderably slower than with the corresponding terminal olefins. Noreaction occurred between precursor complex 10 and3,3-dimethyl-1-butene, and the steric interaction between the metalfragment and the incoming olefin is also presumed to be responsible forthe slow reaction with 20 equiv. 3-methyl-1-butene. The expectedalkylidene RuCl₂(═CH^(i)Pr)(PCy₃)₂ was identified by NMR, but itsconcentration remained small and constant throughout the reaction. After6 hours, initiation was complete and methylidene complex 19 was isolatedas the sole reaction product. If alkylidene forms of RuCl₂(═CHR)(PCy₃)₂of complexes 20-22 are not isolated immediately after formation, slowreaction with excess olefin results in the formation ofRuCl₂(═CH₂)(PCy₃)₂ (complex 19) within 10-15 hours (eq. 8).

As proposed in the reaction scheme I below, complex 10 is likely toreact with a terminal olefin to rapidly form a metallocyclobutaneintermediate I, in that the two substituents (Ph and R) are in1,3-position for steric reasons. Productive cleavage of the intermediatemetallacycle leads to the formation of alkylidene complexes 20-22 askinetic products.

On extended reaction times, alkylidene complexes RuCl₂(═CHR)(PCy₃)₂(complexes 20-22) undergo a slow reaction with excess olefin to formmethylidene complex 19 presumably through intermediatemetallocyclobutane II. RuCl₂(═CH₂)(PCy₃)₂ (complex 19) appears to be thethermodynamic product as it will not metathesize α-olefins in diluteconditions.

Metathesis of Conjugated and Cumulated Olefins

Treatment of RuCl₂(═CHPh)(PCy₃)₂ (complex 10) with a tenfold excess of1,3-butadiene and 1,2-propadiene resulted in the high-yield formation ofvinylalkylidene RuCl₂(═CH—CH═CH₂)(PCy₃)₂ (complex 23) and vinylideneRuCl₂(═C═CH₂)(PCy₃)₂ (complex 24), respectively (eq. 5). The formercomplex cannot be synthesized via ring-opening of cyclopropene.

The spectroscopic data for these complexes is similar to those ofrelated compounds RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (complex B) andRuCl₂(═C═CH-t-Bu)(PPh₃)₂. In contrast to observations made in thesynthesis of RuCl₂(═CHR)(PCy₃)₂ [R=Me (complex 20), Et (complex 21),n-Bu (complex 22)], that no methylidene RuCl₂(═CH₂)(PCy₃)₂ (complex 19)was formed at extended reaction times can be explained by the lowactivity of complexes 23 and 24 towards their olefinic precursors.However, both complexes 23 and 24 exhibit ROMP-activity that, in thecase of the former, was evidenced by comparatively slow polymerizationof cyclooctene (PDI=2.0). Vinylidene complex 24 rapidly polymerizednorbornene, although relatively slow initiation can be inferred by thelack of the characteristic color change, and both compounds are inactivefor metathesis of acyclic olefins.

Introduction of Functional Groups via Metathesis

Although less active than their early transition metal counterparts,ruthenium alkylidenes have broader synthetic utility due to theirtolerance of functional groups and protic media. The inventors haveshown that vinylalkylidenes RuCl₂(═CH—CH═CPh₂)(PR₃)₂ (R=Ph, complex A;or R=Cy, complex B) react readily with electron-rich olefins, such asvinyl ethers H₂C═CH—OR′, to yield metathesis-inactiveRuCl₂(═CH—OR′)(PR₃)₂. This irreversible reaction has been extensivelyutilized by the inventors for the endcapping of growing polymer chains.Electron-deficient olefins are not metathesized by thetriphenylphosphine catalyst RuCl₂(═CH—CH═CPh₂)(PPh₃)₂ (complex A), andthe tricyclohexylphosphine catalyst RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (complexB) displays only limited activity towards these substrates. However, theenhanced activity of the benzylidene catalyst complex 10 promptedfurther exploration of this reaction. As shown in eq. 6, metathesis offunctionalized olefins catalyzed by benzylidene complex 10 is notlimited to electron-rich olefins, such as allyl acetate, but alsoincludes electron-deficient alkenes, such as allyl chloride. Benzylidenecomplex 10, will also undergo efficient metathesis of unprotecteden-ols, as shown with 4-pentene-1-ol, to generate the correspondinghydroxy alkylidene RuCl₂(═CH(CH₂)₃₀H)(PCy₃)₂ (complex 27) (eq. 6).

Compounds 25-27 were readily isolated and fully characterized. In allcases the alkylidene H_(o), resonances appeared as triplets due tocoupling with the vicinal CH₂ groups. Alkylidenes 25-27 are active inROMP of low strained olefins, which makes them attractive catalysts forthe synthesis of telechelic and other functionalized polymers.

USE OF ALKYLIDENE COMPLEXES AS METATHESIS CATALYSTS

Kinetic Studies of the Polymerization of Norbornene Catalyzed byRuCl₂(═CH-p-C₆H₄X)(PPh₃)₂ (Complexes 3-9)

Complexes 3-9 polymerize norbornene at a rate of .apprxeq.150equiv./hour in CH₂Cl₂ at RT to give polynorbornene in quantitativeyields. All reactions were accompanied by a characteristic color changefrom green-brown to orange that indicates complete initiation. Theresulting polymers are approximately 90% trans as determined by ¹H NMR.However, the present catalysts produce nearly monodispersed polymers(PDIs=1.04-1.10, compared to 1.25 for RuCl₂(═CH—CH═CPh₂)(PPh₃)₂)(complex A), consistent with measured initiation rates. As observed forRuCl₂(═CH—CH═CPh₂)(PPh₃)₂ (complex A), complexes 3-9 fulfill the generalcriteria for living systems since the propagating alkylidene (¹H NMR: δ17.79 ppm (dt)) is stable throughout the reaction, and the molecularweights of the polymers display a linear dependence on the[catalyst]/[monomer] ratio.

The influence of the para-substituents in the alkylidene moiety on themetathesis activity was qualitatively assessed. Catalysts based oncomplexes 3-9 (RuCl₂(═CH-p=C₆H₄X)(PPh₃)₂, [Ru]=0.022 M) were treatedwith norbornene ([monomer]=0.435 M) in CH₂Cl₂ solution. The pseudofirst-order rate constants for initiation and propagation were obtainedby integrating the H_(α) resonances of complexes 3-9 against thecorresponding resonance of the propagating alkylidene species, andmonitoring the decreasing monomer concentration against an internalferrocene standard, respectively. The derived values of k_(i) and k_(p)are listed in Table III.

TABLE III Initiation Rate Propagation Rate Constant, k_(i) Constant,k_(p) Complex X (×10⁻³/mol · sec×) (×10⁻³/mol · sec) k_(i)/k_(p) 3 H11.5 1.28 9.0 4 NMe₂ 3.32 1.28 2.6 5 OMe 3.34 1.28 2.6 6 Me 3.69 1.282.9 7 F 6.19 1.28 4.8 8 Cl 1.56 1.28 1.2 9 NO₂ 2.91 1.28 2.3 a For |Ru|= 0.022M; |norbornene| = 0.435M in C₆D₆ at 17° C.

As can be seen in Table III, the electronic effect of X inRuCl₂(═CH-p-C₆H₄X)(PPh₃)₂ on initiation rate seems to be relativelysmall: the rate in the fastest case (X=H [complex 3]) was approximately10 times higher than in the slowest (X=Cl [complex 8]). A general trendconcerning the electronic influence of the substituents X was notobserved. Under similar reaction conditions withRuCl₂(═CH—CH═CPh₂)(PPh₃)₂ (complex A) as catalyst, observed initiationwas <50%. When norbornene consumption was complete, uninitiated carbenewas spectroscopically identified. The extrapolated ratio ofk_(i)/k_(p)=6×10⁻³ is approximately 1000 times smaller than thatobserved for complexes 3-9. These results suggest that conjugation seemsto decrease k_(i), presumably by lowering the ground state energy of thestarting arylidenes for complexes 3-9 relative to the likelymetallocyclobutane intermediate. Although benzylidene forms of complexes3-9 are better initiators than RuCl₂(═CH—CH═CPh₂)(PPh₃)₂ (Complex A),application of the former as metathesis catalysts is similarly limitedto ROMP of relatively high-strained cyclic olefins, such as norborneneand cyclobutene derivatives, whose calculated strain energies exceed10-15 kcal/mol.

ROMP Activity of RuCl₂(═CH-p-C₆H₄X)(PCy₃)₂ (Complexes 10-16)

Benzylidenes RuCl₂(═CH-p-C₆H₄X)(PCy₃)₂ (complexes 10-16) are extremelyactive ROMP-catalysts compared to their PPh₃ analogs complexes 3-9.Except for norbornene, ROMP of highly strained monomers includingfunctionalized norbornenes, 7-oxanorbornenes, and variously substitutedcyclobutenes was proved to be living and lead to polymers withexceptionally narrow molecular weight distributions (PDIs<1.1). Inanalogy to RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (complex B), complexes 10-16 canalso polymerize low-strain cycloolefins, such as cyclooctene and1,5-cyclooctadiene. Although the corresponding polymers are notmonodispersed (PDI≈1.50-1.60), these polymerizations proceed morerapidly and with significantly lower polydispersities than withRuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (complex B) as catalyst (PDI≈2.50). However,the occurrence of “back-biting” in these reactions causes broader PDIs.Therefore, these polymerizations cannot be considered living, eventhough a propagating alkylidene was observed for ROMP of cyclooctadieneby ¹H NMR (δ 18.88 (t)) with complex 10.

Complex 10 also reacts with cyclooctatetraene in CD₂Cl₂ with completeinitiation, but propagation does not occur, and facile back-biting leadsto the formation of benzene. The increased activity of complexes 10-16compared to RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (Complex B) is attributed to afaster initiation rate. Recently developed catalyst mixtures containing[(cymene)RuCl₂]₂, a bulky tertiary phosphine andtrimethylsilyldiazomethane were found to catalyze ROMP of cyclooctenes.

Metathesis of Acyclic Olefins

The inventors recently showed that vinylalkylideneRuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (Complex B) exhibits metathesis activitytowards acyclic olefins, e.g., cis-2-pentene. Although theturnover-numbers were modest compared to the best of the tungsten andmolybdenum-based catalysts, vinylalkylidene RuCl₂(═CH—CH═CPh₂)(PCy₃)₂(complex B) was the first example of acyclic metathesis induced by aruthenium carbene complex. However, slow initiation was a presentlimitation for its general use as a catalyst. Due to their exceptionallyhigh activity in ROMP, complexes 10-16 were found to be efficientacyclic metathesis catalysts, as representatively shown with benzylideneRuCl₂(═CHPh)(PCy₃)₂ (complex 10), discussed below.

Kinetic Studies with RuCl₂(═CH-p-C₆H₄X)(PCy₃)₂ (Complexes 10-16)

The electronic influence of X on the initiation rates ofRuCl₂(═CH-p-C₆H₄X)(PCy₃)₂ (complexes 10-16) was probed by examiningtheir reactions with 1-hexene. Clean and quantitative conversion to thepentylidene RuCl₂(═CH-n-Bu)(PCy₃)₂ complex 22 was observed in all cases.Pseudo first-order rate constants were measured by integration of theH_(α) resonances of benzylidene complexes 10-16 versus pentylidenecomplex 22. Representative plots are shown in FIGS. 1A and 1B, andinitiation rate constants (k_(i)) are listed in Table IV.

TABLE IV Initiation Rate Constant, l Complex X k_(i) [10⁻³] (1/mol sec)10 H 2.87 11 NMe₂ 0.31 12 OMe 1.01 13 Me 2.15 14 F 1.21 15 Cl 1.37 16NO₂ 1.77 a For [Ru] = 0.01M; [1-hexene] = 0.32M in CD₂Cl₂ at T = 0° C.

As observed for living-ROMP of norbornene with catalystsRuCl₂(═CH-p-C₆H₄X)(PPh₃)₂ (complexes 3-9), the range of k_(i)s among thesubstituted benzylidenes is approximately an order of magnitude.Although no general trend can be discerned, any perturbation to thearomatic π-system (i.e., X≠H) decreases the initiation rate.RuCl₂(═CHPh)(PCy₃)₂ (complex 10) initiated approximately 1000 timesfaster than vinylidene RuCl₂(═CH—CH═CPh₂)(PCy₃)₂ (Complex B) which didnot completely react to give pentylidene complex 22 under theabove-mentioned conditions.

STRUCTURE OF EXEMPLARY COMPLEX

X-ray Diffraction Study of RuCl₂(═CH-p-C₆H₄Cl)(PCy₃)₂ (Complex 15)

Representative of complexes 10-16, the structure of the Cl-substitutedbenzylidene RuCl₂(═CH-p-C₆H₄Cl)(PCy₃)₂ was further confirmed by a singlecrystal X-ray diffraction study. An ORTEP drawing of this complex isshown in FIG. 2, and selected bond lengths and angles are given in TableV below. The analysis reveals distorted square-pyramidal coordinationwith a nearly linear Cl(1)-Ru—Cl(2) angle (167.61°). The carbene unit isperpendicular to the P1-Ru—P2 plane, and the aryl ligand is onlyslightly twisted out of the Cl1-Ru—Cl2 plane. The Ru—C1 bond distance isshorter (1.838(3) Å) than in related compounds RuCl₂(═CH—CH═CPh₂)(PCy₃)₂[d(Ru—C)=1.851(21)] or RuCl(═C(OMe)-CH═CPh₂)(CO)(Pi-Pr₃)₂[RuCl₂(═CH—CH═CPh₂)(PCy₃)₂F₄][d-(Ru—C)=1.874(3), respectively.

TABLE V Bond Lengths [Å] Ru—Cl 1.839(3) Ru—Cl1 2.401(1) Ru—Cl2 2.395(1)Ru—P1 2.397(1) Ru—P2 2.435(1) Bond Angles [°] Cl1—Ru—P1 87.2(1) P1—Ru—C197.5(1) P1—Ru—C12 91.5(1) Cl1—Ru—P2 90.8(1) C1—Ru—P2 101.2(1) Cl1—Ru—C188.7(1) Cl1—Ru—C12 167.6(1) C1—Ru—C12 103.7(1) P1—Ru—P2 161.1(1)C12—Ru—P2 86.5(1)

EXPERIMENTAL SECTION

General Experimental Procedures

All manipulations were performed using standard Schlenk techniques underan atmosphere of argon. Argon was purified by passage through columns ofBASF R3-11 catalyst (Chemalog) and 4 Å molecular sieves (Linde). Solidorganometallic compounds were transferred and stored in anitrogen-filled Vacuum Atmospheres drybox or under an atmosphere ofargon. NMR spectra were recorded with either a QE-300 Plus (300.1 MHz¹H, 75.5 MHz ¹³C), a JEOL GX-400 (399.7 MHz ¹H, 161.9 MHz ³¹P) or aBruker AM 500 (500.1 MHz ¹H, 125.8 MHz ¹³C; 202.5 MHz ³¹P; 470.5 MHz¹⁹F) spectrometer.

Methylene chloride and benzene were passed through columns of activatedalumina and stored under argon. Benzene-d₆ and methylene chloride-d₂were degassed by three continuous freeze-pump-thaw cycles. RuCl₂(PPh₃)₃,tricyclohexylphosphine, and the diazoalkanes H₂CN₂, MeCHN₂, EtCHN₂,PhCHN₂, p-C₆H₄NMe₂CHN₂, p-C₆H₄OMeCHN₂, p-C₆H₄MeCHN₂, p-C₆H₄FCHN₂,p-C₆H₄ClCHN₂ and p-C₆H₄NO₂CHN₂ were prepared according to literatureprocedures. Norbornene was dried over sodium, vacuum transferred andstored under argon. Cyclooctene, 1,5-cyclooctadiene, and1,3,5,7-cyclooctatetraene were dried over CaH₂, distilled and storedunder argon. The following chemicals were obtained from commercialsources and used as received: ethylene, propylene, 1-butene,cis-2-butene, 1-hexene, cis-3-hexene, 3-methyl-1-butene,3,3-dimethyl-1-butene, 1,3-butadiene, 1,2-propadiene, allyl acetate,allyl chloride, 4-pentene-2-ol, diethyl diallyl malonate,triisopropylphosphine, tricyclo-pentylphosphine, pentane, ether,acetone, and methanol.

Synthesis of RuCl₂(═CHMe)(PPh₃)₂ and RuCl₂(═CHEt)(PPh₃)₂

(Complexes 1 and 2)

A solution of RuCl₂(PPh₃)₃ (417 mg, 0.43 mmol) in CH₂Cl₂ (10 mL) wastreated at −78° C. with a −50° C. 0.50 M solution of diazoethane (1.90mL, 0.93 mmol, 2.2 eq.) in ether. Upon addition of diazoethane, a colorchange from orange-brown to green-brown and slight bubbling wereobserved. After the cooling bath was removed, the solution was stirredfor 3 min and then evaporated to dryness. The oily residue was washedseveral times with small quantities of ice-cold ether (3 mL portions)and the remaining olive-green solid RuCl₂(═CHMe)(PPh₃)₂ was dried undervacuum for several hours. Yield=246 mg (78%). ¹H NMR (CD₂Cl₂): δ 18.47(tq, J_(PH)=10.2 Hz, ³J_(HH)=5.1 Hz, Ru═CH), 7.68-7.56 and 7.49-7.36(both m, P(C₆H₅)₃), 2.59 (d, ³J_(HH) 5.1 Hz, CH₃). ¹³C NMR (CD₂Cl₂): δ320.65 (t, J_(PC)=9.9 Hz, Ru═CH), 134.76 (m, o-C of P(C₆H₅)₃), 132.06(m, ipso-C of P(C₆H₅)₃), 130.38 (s, p-C of P(C₆H₅)₃), 128.44 (m, m-C ofP(C₆H₅)₃). ³¹P NMR (CD₂Cl₂): δ 29.99 (s, PPh₃). Anal. Calcd. forC₃₈H₃₄Cl₂P₂Ru: C, 62.99; H, 4.73. Found: C, 63.12; H, 4.61.

In an analogous procedure, RuCl₂(═CHEt)(PPh₃)₂ was prepared, startingwith RuCl₂(PPh₃)₃ (502 mg, 0.52 mmol) and a 0.45 M solution ofdiazopropane (2.56 mL, 1.15 mmol, 2.2 eq.) in ether. An orange-brownmicrocrystalline solid was obtained. Yield=311 mg (81%). ¹H NMR(C₆D₆): δ18.21 (tt, J_(PH)=10.8, ³J_(HH) 6.6 Hz, Ru═CH), 7.91-7.86 and 6.97-6.80(both m, P(C₆H₅)₃), 3.11 (dq, ³J_(HH)=³J_(HH)′=6.6 Hz, CH₂CH₃), 0.79 (t,³J_(HH)=6.6 Hz, CH₂CH₃). ¹³C NMR (CD₂Cl₂): δ 320.88 (t, J_(PC)=10.0 Hz,Ru═CH), 134.36 (m, o-C of P(C₆H₅)₃, 132.27 (m. ipso-C of P(C₆H₅)₃),129.89 (s, p-C of P(C₆H₅)₃), 128.14 (m, m-C of P(C₆H₅)₃), 53.20 (s,CH₂CH₃), 29.74 (s, CH₂CH₃). ³¹P NMR (CD₂Cl₂): δ 30.02 (s, PPh₃). Anal.Calcd. for C₃₉H₃₈Cl₂P₂Ru: C, 63.42; H, 4.91. Found: C, 62.85; H, 4.81.

Synthesis of RuCl₂(═CHPh)(PPh₃)₂ (Complex 3)

A solution of RuCl₂(PPh₃)₃ (2.37 g, 2.47 mmol) in CH₂Cl₂ (20 mL) wastreated at −78° C. with a −50° C. solution of phenyldiazomethane (584mg, 4.94 mmol, 2.0 eq.) in CH₂Cl₂ or pentane (3 mL). A spontaneous colorchange from orange-brown to brown-green and vigorous bubbling wereobserved. After the cooling bath was removed, the solution was stirredfor 5 min and the solution was then concentrated to −3 mL. Upon additionof pentane (20 mL), a green solid was precipitated, separated from thebrown mother-liquid via cannula filtration, dissolved in CH₂Cl₂ (3 mL)and reprecipitated with pentane. This procedure was repeated until themother-liquid was nearly colorless. The remaining grey-greenmicrocrystalline solid was dried under vacuum for several hours.Yield=1.67 g (89%). ¹H NMR (C₆D₆): δ 19.56 (t, J_(PH)=10.2 Hz, Ru═CH),7.80-7.64 and 6.99-6.66 (both m, C₆H₆ and P(C₆H₅)₃). ¹³C NMR (CD₂Cl₂): δ310.12 (t, J_(PC)=11.4 Hz, Ru═CH), 155.36 (s, ipso-C of C₆H₅), 134.91(m, m-C or o-C of P(C₆H₅)₃), 133.97 (d, J_(PC) 19.6 Hz, ipso-C ofP(C₆H₅)₃), 130.44 (s, p-C of P(C₆H₅)₃), 130.03, 128.71 and 127.09 (alls, C₆H₅), 128.37 (s(br.), m-C or o-C of P(C₆H₅)₃). ³¹P NMR (CD₂Cl₂): δ30.63 (s, PPh₃). Anal. Calcd. for C₄₃H₃₈Cl₂P₂Ru: C, 65.65; H, 4.61; P.7.87. Found: C, 65.83; H, 4.59; P. 7.93.

Synthesis of RuCl₂(═CH-p-C₆H₄NMe₂)(PPh₃)₂ (Complex 4)

A solution of RuCl₂(PPh₃)₃ (466 mg, 0.49 mmol) in CH₂Cl₂ (10 mL) wastreated at −78° C. with a −50° C. solution of p-C₆H₄NMe₂CHN₂ (160 mg,0.98 mmol, 2.0 eq.) in CH₂Cl₂ (3 mL). A spontaneous color change fromorange-brown to brown-green and vigorous bubbling was observed. Afterthe cooling bath was removed, the solution was stirred for 10 min andthen the solvent was removed under vacuum. The brown residue wasdissolved in minimal amounts of CH₂Cl₂ (3 mL), and pentane (20 mL) wasadded to precipitate a green solid. After cannula filtration, thisprocedure was repeated until the filtrate was colorless. The remainingolive-green microcrystalline solid was dried under vacuum for severalhours. Yield=317 mg (78%). ¹H NMR (CD₂Cl₂): δ 18.30 (t, J_(PH)=6.1 Hz,Ru═CH), 7.64 (d, ³J_(HH)=8.7 Hz, o-H of C₆H₄NMe₂), 7.52-7.49 (m, o-H ofP(C₆H₅)₃), 7.42 (t, ³J_(HH)=7.5 Hz, p-H of P(C₆H₅)₃, 7.33 (t,³J_(HH)=7.5 Hz, m-H of P(C₆H₅)₃), 6.32 (d, ³J_(HH)=8.7 Hz, m-H ofC₆H₄NMe₂), 2.96 (s, N(CH₃)₂). ¹³C NMR (CD₂Cl₂): δ 309.68 (t, J_(PC) 11.4Hz, Ru═CH), 152.72 (s, ipso-C of C₆H₄NMe₂), 135.01 (m, m-C or o-C ofP(C₆H₅)₃), 133.57 (s, o-C or m-C of C₆H₄NMe₂), 131.86 (s, C ofP(C₆H₅)₃), 130.20 (s, o-C or m-C of C₆H₄NMe₂), 128.27 (m, m-C or o-C ofP(C₆H₅)₃), 127.54 (s(br.), p-C of C₆H₄NMe₂), 110.61 (d, J_(PC)=21.5 Hz,ipso-C of P(C₆H₅)₃, 40.30 (s, N(CH₃)₂. ³¹P NMR (CD₂Cl₂): δ 34.84 (s,PPh₃). Anal. Calcd. for C₄₅H₄₁Cl₂NP₂Ru: C, 65.14; H, 4.98; N, 1.69.Found: C, 65.28; H, 4.97; N, 1.80.

Synthesis of RuCl₂(═CH-p-C₆H₄OMe)(PPh₃)₂ (Complex 5)

A solution of RuCl₂(PPh₃)₃ (561 mg, 0.59 mmol) in CH₂Cl₂ (12 mL) wastreated at −78° C. with a −40° C. solution of p-C₆H₄OMeCHN₂ (87 mg, 0.59mmol, 1.0 eq.) in CH₂Cl₂ (3 mL). A spontaneous color change fromorange-brown to brown-green and vigorous bubbling was observed. Afterthe cooling bath was removed, the solution was stirred for 5 min andthen the solvent was removed under vacuum. The brown-green residue wasdissolved in minimal amounts of CH₂Cl₂ (2 mL), and pentane (20 mL) wasadded to precipitate a brown solid. The brown-green solution wasseparated via cannula filtration and dried under vacuum. The remainingolive-green solid, complex 5, was repeatedly washed with ether (10 mLportions) and dried under vacuum for several hours. Yield w. 400 mg(83%). ¹H NMR, (C₆D₆): δ 19.39 (t, J_(PH)=8.7 Hz, Ru═CH), 7.85-7.72 and7.03-6.80 (both m, C₆H₄OMe and P(C₆H₅)₃, 6.41 (d, ³J_(HH)=8.7 Hz, m-H ofC₆H₄OMe), 3.22 (s, OCH₃). ¹³C NMR (CD₂Cl₂); δ 309.20 (t, J_(PC)=10.7 Hz,Ru═CH), 147.42 (s, ipso-C of C₆H₄OMe), 135.56 (pseudo-t, m-C or o-C ofP(C₆H₆)₃, 133.98 (s, o-C or m-C of C₆H₄OMe), 131.46 (s, p-C ofP(C₆H₅)₃), 130.43 (s, o-C or m-C of C₆H₄OMe), 128.40 (pseudo-t, m-C oro-C of P(C₆H₅)₃, 126.82 (s, p-C of C₆H₄OMe), 113.95 (d, J_(PC)=21.4 Hz,ipso-C of P(C₆H₅)₃, 55.77 (s, OCH₃). ³¹P NMR (CD₂Cl₂): δ 32.50 (s,PPh₃). Anal. Calcd. for C₄₄H₃₈Cl₂OP₂Ru: C, 64.71; H, 4.69. Found: C,65.23; H, 4.78.

Synthesis of RuCl₂(═CH-p-C₆H₄Me)(PPh₃)₂ (Complex 6)

In a technique analogous to that used in synthesizing complex 5,RuCl₂(═CH-p-C₆H₄Me)(PPh₃)₂ was prepared from RuCl₂(PPh₃)₃ (350 mg, 0.37mmol) and p-C₆H₄MeCHN₂ (48 mg, 0.37 mmol, 1.0 eq.) A brownmicrocrystalline solid was obtained. Yield=258 mg (87%). ¹H NMR (C₆D6):.delta.519.55 (t, J_(PH)=9.6 Hz, Ru═CH), 7.84-7.63 and 7.02-6.80 (bothm, C₆H₄Me and P(C₆H₅)₃), 6.53 (d, ³J_(HH)=7.8 Hz, m-H of C₆H₄Me), 1.68(s, CH₃). ¹³C NMR (CD₂Cl₂): δ 309.17 (t, J_(PC)=10.9 Hz, Ru═CH), 153.34(s, ipso-C of C₆H₄Me), 135.50 (s, o-C or m-C of C₆H₄OMe), 134.96 (m, m-Cor o-C of P(C₆H₅)₃, 132.13 (s, p-C of P(C₆H₅)₃), 130.39 (s, o-C or m-Cof C₆H₄Me), 128.34 (m, m-C or o-C of P(C₆H₅)₃), 126.76 (s, p-C ofC₆H₄Me), 115.23 (d, J_(PC)=21.4 Hz, ipso-C of P(C₆H₅)₃), 40.92 (s, CH₃).³¹P NMR (CD₂Cl₂): δ 31.29 (s, PPh₃). Anal. Calcd. for C₄₄H₃₈Cl₂P₂Ru: C,66.00; H, 4.78. Found: C, 65.90; H, 4.75.

Synthesis of RuCl₂(═CH-p-C₆H₄F)(PPh₃)₂ (Complex 7)

In a technique analogous to that used in synthesizing complex 3,RuCl₂(═CH-p-C₆H₄F)(PPh₃)₂ was prepared from RuCl₂(PPh₃)₃ (960 mg, 1.00mmol) and p-C₆H₄FCHN₂ (272 mg, 2.00 mmol, 2.0 eg.). Complex 7 wassynthesized in analogy to complex 3. An olive-green microcrystallinesolid was obtained. Yield=716 mg (89%). ¹H NMR (CD₂Cl₂): δ 19.24 (t,J_(PH)=9.0 Hz, Ru═CH), 7.65-7.62 (m, o-H of C₆H₄F), 7.50-7.44 and7.35-7.32 (both m, P(C₆H₅)₃, 6.62 (t, ³J_(HH)=³J_(HF)=8.9 Hz, m-H ofC₆H₄F), 152.21 (s, ipso-C of C₆H₄F), 134.95 (m, m-C or o-C of P(C₆H₅)₃),134.04 (d, J_(CF)=19.5 Hz, m-C of C₆H₄F), 130.56 (s, p-C of P(C₆H₅)₃),130.08 (d, J_(CF)=8.7 Hz, o-C of C₆H₄F), 128.47 (m, m-C or o-C ofP(C₆H₅)₃, 115.67 (d, J_(PC)=21.8 Hz, ipso-C of P(C₆H₅)₃). ³¹P NMR(CD₂Cl₂): δ 31.03 (s, PPh₃). ¹⁹F NMR (CD₂Cl₂): δ 45.63 (s, C₆H₄F). Anal.Calcd. for C₄₃H₃₅Cl₂FP₂Ru: C, 64.18; H, 4.38. Found: C, 64.42; H, 4.42.

Synthesis of RuCl₂(═CH-p-C₆H₄Cl)(PPh₃)₂ (Complex 8)

In a technique analogous to that used in example 2,RuCl₂(═CH-p-C₆H₄Cl)(PPh₃)₂ was prepared from RuCl₂(PPh₃)₃ (350 mg, 0.37mmol) and p-C₆H₄ClCHN₂ (111 mg, 0.73 mmol, 2.0 eq.) A greenmicrocrystalline solid was obtained. Yield=246 mg (82%). ¹H NMR(CD₂Cl₂); δ 19.27 (t, J_(PH)=9.2 Hz, Ru═CH), 7.51-7.44, 7.35-7.32 and6.67-6.63 (all m, C₆H₄Cl and P(C₆H₅)₃), 6.86 (d, ³J_(HH)=8.8 Hz, m-H ofC₆H₄Cl). ¹³C NMR (CD₂Cl₂): δ 307.34 (t, J_(PC)=10.6 Hz, Ru—CH), 153.82(s, ipso-C of C₆H₄Cl), 134.91 (m, m-C or o-C of P(C₆H₅)₃), 130.58 (s,p-C of P(C₆H₅)₃, 128.87, 128.81 and 127.85 (all s, C₆H₄Cl), 128.48(s(br.), m-C or o-C of P(C₆H₅)₃, 115.90 (d, J_(PC)=21.7 Hz, ipso-C ofP(C₆H₅)₃). ³¹P NMR (CD₂Cl₂): δ 30.47 (s, PPh₃). Anal. Calcd. forC₄₃H₃₅Cl₃P₂Ru: C, 62.90; H. 4.30. Found: C, 62.87; H, 4.40.

Synthesis of RuCl₂(═CH-p-C₆H₄NO₂)(PPh₃)₂ (Complex 9)

In a technique analogous to that used in synthesizing complex 3,RuCl₂(═CH-p-C₆H₄NO₂)(PPh₃)₂₁ complex 9 was prepared from RuCl₂(PPh₃)₃(604 mg, 0.63 mmol) and p-C₆H₄NO₂CHN₂ (206 mg, 1.25 mmol, 2.0 eq.) A tanmicrocrystalline solid was obtained. Yield=398 mg (76%). ¹H NMR(CD₂Cl₂): δ 19.47 (t, J_(PH)=10.8 Hz, Ru═CH), 7.88-7.67, 7.38-7.33 and7.02-6.71 (all m, C₆H₄NO₂ and P(C₆H₅)₃. ¹³C NMR (CD₂Cl₂): δ 313.43 (t,J_(PC)=11.2 Hz, Ru═CH), 158.40 (s, ipso-C of C₆H₄NO₂), 148.11 (s, p-C ofC₆H₄NO₂), 135.49 (m, m-C or o-C of P(C₆H₅)₃), 132.21 (s, m-C ofC₆H₄NO₂), 130.91 (s, p-C of P(C₆H₅)₃, 130.72 (s, o-C of C₆H₄NO₂), 128.86(m, m-C or o-C of P(C₆H₄)₃, 116.03 (d, J_(PC)=21.6 Hz, ipso-C ofP(C₆H₅)₃). ³¹P NMR (CD₂Cl₂): δ 32.27 (s, PPh₃). Anal. Calcd. forC₄₃H₃₅Cl₂NO₂P₂Ru: C, 62.10; H, 4.24; N, 1.68. Found: C, 62.31; H, 4.66;N, 1.84.

Synthesis of RuCl₂(═CHPh)(PCy₃)₂ (Complex 10)

A solution of RuCl₂(═CHPh)(PPh₃)₂ (242 mg, 0.31 mmol) in CH₂Cl₂ (10 mL)was treated with a solution of tricyclohexylphosphine (190 mg, 0.68mmol; 2.2 eq.) in CH₂Cl₂ (3 mL) and stirred at RT for 30 min. Thesolution was filtered, and the solvent was removed under vacuum. Theresidue was repeatedly washed with acetone or methanol (5 mL portions)and dried in vacuo. A purple microcrystalline solid was obtained. Yield290 mg (89%). ¹H NMR (CD₂Cl₂): δ 20.02 (s, Ru═CH) (s, Ru═CH), 8.44 (d,³J_(HH)=7.6 Hz, o-H of C₆H₅), 7.56 (t, ³J_(HH)=7.6 Hz, p-H of C₆H₅),7.33 (t, ³J_(HH)=7.6 Hz, m-H of C₆H₅), 2.62-2.58, 1.77-1.67, 1.46-1.39and 1.25-1.16 (all m, P(C₆H₁₁)₃. ¹³C NMR (CD₂Cl₂): δ 294.72 (s, Ru═CH),153.17 (s, ipso-C of C₆H₅), 131.21, 129.49 and 129.27 (all s, C₆H₅),32.49 (pseudo-t, J_(app)=9.1 Hz, ipso-C of P(C₆H₁₁)₃), 30.04 (s, m-C ofP(C₆H₁₁)₃, 28.24 (pseudo-t, J_(app)=4.5 Hz, o-C of P(C₆H₁₁)₃), 26.96 (s,p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 36.61 (s, PCy₃). Anal. Calcd. forC₄₃H₇₂Cl₂P₂Ru: C, 62.76; H, 8.82. Found: C, 62.84; H, 8.71.

One-Pot Synthesis of RuCl₂(═CHPh)(PCy₃)₂ (Complex 10)

A solution of RuCl₂(PPh₃)₃ (4.0 g, 4.17 mmol) in CH₂Cl₂ (40 mL) wastreated at −78° C. with a −50° C. solution of phenyldiazomethane (986mg, 8.35 mmol, 2.0 eq.) in pentane (10 mL). Upon addition of the diazocompound, an instantaneous color change from orange-brown to green-brownand vigorous bubbling was observed. After the reaction mixture wasstirred at −70° C. to −60° C. for 5-10 min, an ice-cold solution oftricyclohexylphosphine (2.57 g, 9.18 mmol, 2.2 eq.) in CH₂Cl₂ was addedvia syringe. Accompanied by a color change from brown-green to red, thesolution was allowed to warm to RT and stirred for 30 min. The solutionwas filtered, concentrated to half of the volume and filtrated. Methanol(100 mL) was added to precipitate a purple microcrystalline solid,complex 10, that was filtered off, washed several times with acetone andmethanol (10 mL portions), and dried under vacuum for several hours.Yield 3.40 g (99%).

Synthesis of RuCl₂(═CH-p-C₆H₄NMe₂)(PCy₃)₂ (Complex 11)

Starting with RuCl₂(═CH-p-C₆H₄NMe₂)(PPh₃)₂ (316 mg, 0.38 mmol) andtricyclohexylphosphine (235 mg, 0.84 mmol, 2.2 eq.)RuCl₂(═CH-p-C₆H₄NMe₂)(PCy₃)₂ was obtained as a green microcrystallinesolid in a procedure analogous to that used in synthesizing complex 10.Yield 284 mg (86%). ¹H NMR (CD₂Cl₂): δ 18.77 (s, Ru═CH), 8.25-8.14(s(vbr.), o-H of C₆H₄NMe₂), 6.55 (d, ³J_(HH)=7.2 Hz, m-H of C₆H₄NMe₂),2.97 (s, N(CH₃)₂), 2.63-2.61, 1.80-1.67, 1.43-1.41 and 1.21-1.17 (all m,P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂): δ 286.13 (s(br.); Ru═CH), 151.28 (s;ipso-C of C₆H₄NMe₂), 144.80, 134.85 and 110.50 (all s; C₆H₄NMe₂), 40.30(s, N(CH₃)₂, 32.54 (pseudo-t, J_(app)=8.2 Hz, ipso-C of P(C₆H₁₁)₃) 30.10(s, m-C of P(C₆H₁₁)₃), 28.36 (m, o-C of P(C₆H₁₁)₃), 27.07 (s, p-C ofP(C₆H₁₁)₃. ³¹P NMR (CD₂Cl₂); δ 34.94 (s, PCy₃). Anal. Calcd. forC₄₅H₇₇Cl₂NP₂Ru: C, 62.41; H, 8.96; N, 1.62. Found: C, 62.87; H, 9.04; N,1.50.

Synthesis of RuCl₂(═CH-p-C₆H₄OMe)(PCy₃)₂ (Complex 12)

Starting with RuCl₂(═CH-p-C₆H₄OMe)(PPh₃)₂ (171 mg, 0.21 mmol) andtricyclohexylphosphine (130 mg, 0.46 mmol, 2.2 eq.),RuCl₂(═CH-p-C₆H₄OMe)(PCy₃)₂ was obtained as a dark-purplemicrocrystalline solid, in a technique analogous to that used insynthesizing complex 10. Yield 152 mg (85%). ¹H NMR (CD₂Cl₂): δ 19.48(s, Ru═CH), 8.43 (s(br.), o-H of C₆H₄OMe), 6.82 (d, J_(HH)=8.6 Hz, m=Hof C₆H₄OMe), 3.82 (s, OCH₃), 2.64-2.59, 1.78-1.68, 1.46-1.39 and1.26-1.15 (all m, P(C₆H₁₁)₃, ¹³C NMR (CD₂Cl₂); δ 290.90 (s(br.), Ru═CH),148.34 (s, ipso-C of C₆H₄OMe), 134.91 132.30 and 128.83 (all s,C₆H₄OMe), 55.81 (s, OCH₃), 32.51 (pseudo-t, J_(app)=9.1 Hz, ipso-C ofP(C₆H₁₁)₃), 30.06 (s, m-C of P(C₆H₁₁)₃), 28.28 (pseudo-t, J_(app)=5.2Hz, o-C of P(C₆H₁₁)₃), 27.00 (s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ35.83 (s, PCy₃). Anal. Calcd. for C₄₄H₇₄C12OP₂Ru: C, 61.96; H, 8.74.Found: C, 62.36; H, 8.71.

Synthesis of RuCl₂(═CH-p-C₆H₄Me)(PCy₃)₂ (Complex 13)

Starting with RuCl₂(═CH-p-C₆H₄Me(PPh₃)₂ (416 mg, 0.52 mmol) andtricyclohexylphosphine (321 mg, 1.14 mmol, 2.2 eq.),RuCl₂(═CH-p-C₆H₄Me)(PCy₃)₂ was obtained as a bright-purplemicrocrystalline solid, in a technique analogous to that used insynthesizing complex 10. Yield 385 mg (88%). ¹H NMR (CD₂Cl₂): δ 19.80(s, Ru═CH), d, ³J_(HH)=7.6 Hz, o-H of C₆H₄Me), 7.13 (d, ³J_(HH)=7.6 Hz,m-H of C₆H₄Me), 2.08 (s, CH₃), 2.62-2.58, 1.77-1.67, 1.43-1.40 and1.22-1.17 (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂): δ 293.86 (t, J_(PC)=8.3Hz, Ru═CH), 141.48 (s, ipso-C of C₆H₄Me), 131.56 and 129.85 (both s,C₆H₄Me), 32.52 (pseudo-t, J_(app)=9.2 Hz, ipso-C of P(C₆H₁₁)₃), 30.07(s, m-C of P(C₆H₁₁)₃), 28.26 (pseudo-t, J_(app)=4.1 Hz, o-C ofP(C₆H₁₁)₃), 27.00 (s, p-C of P(C₆H₁₁)₃), 22.39 (s, CH₃). ³¹P NMR(CD₂Cl₂): δ 36.09 (s, PCy₃). Anal. Calcd. for C₄₄H₇₄Cl₂P₂Ru: C, 63.14;H, 8.91. Found: C, 63.29; H, 8.99.

Synthesis of RuCl₂ (═CH-p-C₆H₄F)(PCy₃)₂ (Complex 14)

Starting with RuCl₂ (═CH-p-C₆H₄F)(PPh₃)₂ (672 mg, 0.84 mmol) andtricyclohexylphosphine (515 mg, 1.84 mmol, 2.2 eq.),RuCl₂(═CH-p-C₆H₄F)(PCy₃)₂ was obtained as a purple microcrystallinesolid, in a technique analogous to that used in synthesizing complex 10.Yield, 583 mg (83%). ¹H NMR (CD₂Cl₂): δ 19.86 (s, Ru═CH), 8.52-8.50(s(br.), o-H of C₆H₄F), 7.00 (dd, ³J_(HH)=3JHF=8.8 Hz, m-H of C₆H₄F),2.63-2.59, 1.77-1.68, 1.47″1.40 and 1.26-1.17 (all m, P(C₆H₁₁)₃). ¹³CNMR (CD₂Cl₂): δ 291.52 (t, J_(PC)=8.6 HZ, Ru═CH), 162.10 (d,J_(CF)=254.3 Hz, p-C of C₆H₄F), 150.57 (s, ipso-C of C₆H₄F), 134.10 (d,J_(CF)=8.9 Hz, o-C of C₆H₄F), 116.00 (d, j CF=21.3 Hz, m-C of C₆H₄F),32.49 (pseudo-t, J_(app)=9.3 Hz, ipso-C of P(C₆H₁₁)₃), 30.05 (s, m-C ofP(C₆H₁₁)₃), 28.22 (pseudo-t, J_(app)=5.2 Hz, o-C of P(C₆H₁₁)₃), 26.94(s, p-C of P(C₆H₁₁)₃. ³¹P NMR (CD₂Cl₂): δ 36.60 (s, PC_(y3)). ¹⁹F NMR(CD₂Cl₂): δ 45.47 (s, C₆H₄F). Anal. Calcd. for C₄₃H₇₁Cl₂FP₂Ru: C, 61.41;H, 8.51. Found: C, 61.32; H, 8.59.

Synthesis of RuCl₂(═CH-p-C₆H₄Cl)(PCy₃)₂ (Complex 15)

Starting with RuCl₂ (═CH-p-C₆H₄Cl)(PPh₃)₂ (543 mg, 0.66 mmol) andtricyclohexylphosphine (408 mg, 1.45 mmol, 2.2 eq.), RuCl₂(═CH-p-C₆H₄Cl)(PCy₃)₂ was obtained as a purple microcrystalline solid ina technique analogous to that used in synthesizing complex 10. Yield 493mg (87%). ¹H NMR (CD₂Cl₂): δ 19.98 (s, Ru═CH), 8.43 (d, ³J_(HH)=8.7 Hz,o-H of C₄H₄Cl), 7.29 (d, ³J_(HH)=8.7 Hz, m-H of C₆H₄Cl), 2.63-2.58,1.76-1.68, 1.46-1.41 and 1.25-1.17 (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂):δ 291.52 (t, J_(PC)=8.0 HZ, Ru═CH), 151.81 (s, ipso-C of C₆H₄Cl), 134.64(s, p-C of C₆H₄Cl), 132.56 and 129.51 (both s, o-C and m-C of C₆H₄Cl),32.51 (pseudo-t, J_(app)=8.9 Hz, ipso-C of P(C₆H₁₁)₃), 30.06 (s, m-C ofP(C₆H₁₁)₃), 28.22 (pseudo-t, J_(app)=5.2 Hz, o-C of P(C₆H₁₁)₃),26.96 (s,p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 36.81 (s, PC_(y3)) Anal. Calcd.for C₄₃H₇₁Cl₂FP₂Ru: C, 60.24; H, 8.35. Found: C, 60.22; H, 8.45.

Synthesis of RuCl₂(═CH-p-C₆H₄NO₂)(PCy₃)₂ (Complex 16)

Starting with RuCl₂(═CH-p-C₆H₄NO₂)(PPh₃)₂ (609 mg, 0.73 mmol) andtricyclohexylphosphine (452 mg, 1.61 mmol, 2.2 eq.),RuCl₂(═CH-p-C₆H₄NO₂)(PCy₃)₂ was obtained, in a procedure analogous tothat in example 11, as a red-purple microcrystalline solid. Yield 527 mg(83%). ¹H NMR (CD₂Cl₂): δ 20.71 (s, Ru═CH), 8.64 (d, ³J_(HH)=8.4 Hz, o-Hof C₆H₄NO₂), 8.13 (d, ³J_(HH)=8.4 Hz, m-H of C₆H₄NO₂), 2.63-2.58,1.73-1.68, 1.47-1.40 and 1.26-1.17 (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂)δ 289.07 (t, J_(PC)=7.6 Hz, Ru═CH), 155.93 (s, ipso-C of C₆H₄NO₂),145.34 (s, p-C of C₆H₄NO₂), 131.22 and 125.06 (both s, o-C and m-C ofC₆H₄NO₂), 32.57 (pseudo-t, J_(app)=9.2 Hz, ipso-C of P(C₆H₁₁)₃), 30.05(s, m-C of P(C₆H₁₁)₃), 28.16 (pseudo-t, J_(app)=4.1 Hz, o-C ofP(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 38.11 (s, PC_(y3)). Anal. Calcd. forC₄₃H₇₁Cl₂NO₂P₂Ru: C, 59.50; H, 8.25; N, 1.61. Found: C, 59.18; H, 8.25;N, 1.49.

One-Pot Synthesis of RuCl₂(═CHPh)(PCp₃)₂ (Complex 17)

Complex 17 is obtained in analogy to complex 10 as a purplemicrocrystalline solid, using RuCl₂(PPh₃)₃ (4.00 g, 4.17 mmol),phenyldiazomethane (986 mg, 8.35 mmol, 2.0 eq.), andtricyclopentylphosphine (2.19 g, 9.18 mmol, 2.2. eq.). Due to the bettersolubility of 17, only methanol is used for the washings. Yield 2.83 g(92%). ¹H NMR (CD₂Cl₂): δ 20.20 (s, Ru═CH), 8.47 (d, ³J_(HH)=7.5 Hz, o-Hof C₆H₅), 7.63 (t, ³J_(HH)=7.5 Hz, p-H of C₆H₅), 7.36 (t, ³J_(HH)=7.5Hz, m-H of C₆H₅), 2.68-2.62, 1.81-1.77, 1.62-1.52 and 1.49-1.44 (all m,P(C₅H₈)₃). ¹³C NMR (CD₂Cl₂): δ 300.52 (t, J_(PC)=7.6 Hz, Ru═CH), 153.38(s, ipso-C of C₆H₅), 130.99, 129.80 and 129.53 (all s, C₆H₅) 35.54(pseudo-t, J_(app)=11.2 Hz, ipso-C of P(C₅H₉)₃) 29.99 and 26.39 (both s,P(C₅H₉)₃). ³¹P NMR (CD₂Cl₂): δ 29.96 (s, PCp₃). Anal. Calcd. forC₃₇H₆₀Cl₂P₂Ru: 60.15; H, 8.19. Found: C, 60.39; H, 8.21.

One-Pot Synthesis of RuCl₂(═CHPh)(PiPr₃)₂ (Complex 18)

Complex 18 is obtained in analogy to complex 17 as a purplemicrocrystalline solid, using RuCl₂(PPh₃)₃ (4.00 g, 4.17 mmol),phenyldiazomethane (986 mg, 8.35 mmol, 2.0 eq.), andtriisopropylphosphine (1.79 mL, 9.18 mmol, 2.2. eq.). Yield 2.26 g(93%). ¹H NMR (CD₂Cl₂): δ 220.10 (s, Ru═CH), 8.52 (d, ³J_(HH)=7.6 Hz,o-H of C₆H₅, 7.36 (t, J_(HH)=7.6 Hz, p-H of C₆H₅), 7.17 (t, ³J_(HH)=7.6Hz, m-H of C₆H₅), 2.88-2.85, (m, PCHCH₃); 1.19 (dvt, N=13.6 Hz, PCHCH₃).¹³C NMR (CD₂Cl₂): δ 296.84 (s(br.), Ru═CH), 152.81 (s, ipso-C of C₆H₅),131.37, 129.54 and 129.20 (all s, C₆H₅) 22.99 (vt,N=²J_(PC)+⁴J_(PC)=18.9 Hz, PCHCH₃), 19.71 (s, PCHCH₃). ³¹P NMR (CD₂Cl₂):δ 45.63 (s, PiPr₃). Anal. Calcd. for C₂₅H₄₈Cl₂P₂Ru: C, 51.54; H, 8.31.Found: C, 51.69; H, 8.19.

Synthesis of RuCl₂(═CH₂)(PCy₃)₂ (Complex 19)

A solution of RuCl₂(═CHPh)(PCy₃)₂ (821 mg, 1.00 mmol) in CH₂Cl₂ (15 mL)was stirred under an atmosphere of ethylene for 15 min at RT. Thesolvent was removed under vacuum, the residue repeatedly washed withacetone or pentane (5 mL) and dried under vacuum for several hours. Aburgundy microcrystalline solid was obtained. Yield 745 mg (quant.). ¹HNMR (CD₂Cl₂): δ 18.94 (s, Ru═CH₂), 2.50-2.44, 1.81-1.70, 1.49-1.43 and1.25-1.23 (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂): δ 294.71 (t, J_(PC)=7.6Hz, J_(CH)=164.0 Hz (gated decoupled), Ru═CH), 31.051 pseudo-t,J_(app)=9.6 Hz, ipso-C of P(C₆H₁₁)₃), 29.58 (s, m-C of P(C₆H₁₁)₃), 28.20(pseudo-t, J_(app)=5.3 Hz, o-C of P(C₆H₁₁)₃), 26.94 (s, p-C ofP(C₆H₁₁)₃) ³¹P NMR (CD₂Cl₂): δ 43.74 (s, PCy₃). Anal. Calcd. forC₃₇H₆₈Cl₂P₂Ru: C, 59.50; H, 9.18. Found: C, 59.42; H, 9.29.

Synthesis of RuCl₂(═CHMe)(PCy₃)₂ (Complex 20)

In a procedure analogous to that used in synthesizing complex 19,RuCl₂(═CHMe)(PCy₃)₂ was obtained as a red-purple microcrystalline solid,using RuCl₂(═CHPh)(PCy₃)₂ (763 mg, 0.93 mmol) and propylene (or2-butene) as starting materials. Yield 691 mg (98%). ¹H NMR (CD₂Cl₂): δ19.26 (q, ³J_(HH)=5.1, Hz, Ru═CH), 2.57 (d, ³J_(HH)=5.1 Hz, CH₃),2.59-2.53, 1.87-1.79, 1.57-1.50 and 1.28-1.23 (all m, P(C₆H₁₁)₃). ¹³CNMR (CD₂Cl₂): δ 316.32 (t, J_(PC)=7.6 Hz, Ru═CH), 49.15 (s, CH₃), 32.37(pseudo-t, J_(app)=9.4 Hz, ipso-C of P(C₆H₁₁)₃), 29.87 (s, m-C ofP(C₆H₁₁)₃), 28.22 (pseudo-t, J_(app)=5.0 Hz, o-C of P(C₆H₁₁)₃), 26.94(s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 35.54 (s, PCy₃). Anal. Calcd.for C₃₈H₇₀Cl₂P₂Ru: C, 59.58; H, 9.27. Found: C, 59.91; H, 9.33.

Synthesis of RuCl₂(═CHEt)(PCy₃)₂ (Complex 21)

In a procedure analogous to that used in synthesizing complex 19,RuCl₂(═CHEt)(PCy₃)₂ was obtained as a red-purple microcrystalline solid,using RuCl₂(═CHPh)(PCy₃)₂ and a tenfold excess of 1-butene (orcis-3-hexene) as starting materials. Yield 616 mg (97%). ¹H NMR(CD₂Cl₂): δ 19.12 (t, ³J_(HH)=5.0 Hz, Ru═CH), 2.79 (dq, ³J_(HH)=5.0,³J_(HH)′=7.1 Hz, CH₂CH₃), 2.55-2.49, 1.84-1.81, 1.54-1.47 and 1.26-1.23(all m, P(C₆H₁₁)₃), 1.35 (t, 3J_(HH)′=7.1 Hz, CH₂CH₃). ¹³C NMR (CD₂Cl₂):δ 322.59 (t, J_(PC)=9.3 Hz, Ru═CH), 53.48 (s, CH₂CH₃), 32.20 (pseudo-t,J_(app)=8.9 Hz, ipso-C of P(C₆H₁₁)₃), 29.85 (s, m-C of P(C₆H₁₁)₃, 29.57(s, CH₂CH₃), 28.22 (pseudo-t, J_(app)=4.6 Hz, o-C of P(C₆H₁₁)₃), 26.88(s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 36.39 (s, PCy₃). Anal. Calcd.for C₃₉H₇₂Cl₂P₂Ru: C, 60.45; H, 9.37. Found: C, 60.56; H, 9.30.

Synthesis of RuCl₂(═CH-n-Bu)(PCy₃)₂ (Complex 22)

In a procedure analogous to that used in synthesizing complex 19,RuCl₂(═CH-n-Bu)(PCy₃)₂ was obtained as a red-purple microcrystallinesolid, using RuCl₂(═CHPh)(PCy₃)₂ (354 mg, 0.43 mmol) and 1-hexene (538L, 4.30 mmol, 10 eq.) as starting materials. Yield 328 mg (95%). ¹H NMR(CD₂Cl₂); δ 19.24 (t, ³J_(HH)=5.1 Hz, Ru═CH), 2.74 (dt, ³J_(HH)=5.1,³J_(HH)′=5.2 Hz, (CHCH₂), 2.56-2.47, 1.82-1.78, 1.70-1.68, 1.54-1.43,1.26-1.22 and 0.95-0.86 (all m, CH₂CH₂ CH₃ and P(C₆H₁₁)₃). ¹³C NMR(CD₂Cl₂): δ 321.13 (t, J_(PC)=7.6 Hz, Ru═CH), 58.85 (s, CHCH₂) 32.25(pseudo-t, J_(app)=9.4 Hz, ipso-C of P(C₆H₁₁)₃), 29.90 (s, m-C ofP(C₈H₁₁)₃), 28.23 (pseudo-t, J_(app)=5.3 Hz, o-C of P(C₆H₁₁)₃, 26.91 (s,p-C of P(C₆H₁₁)₃), 30.53, 22.94 and 14.06 (all s, CH₂CH₂CH₃). ³¹P NMR(CD₂Cl₂): δ 36.05 (s, PCy₃). Anal. Calcd. for C₄₁H₇₆Cl₂P₂Ru: C, 61.32;H, 9.54. Found: C, 61.51; H, 9.71.

Synthesis of RuCl₂(═CHCH═CH₂)(PCy₃)₂ (Complex 23)

1,3-butadiene is slowly bubbled into a solution of complex 10 (703 mg,0.85 mmol) in CH₂Cl₂ (15 mL) for 20 seconds at −20° C. While thesolution is allowed to warm to RT within 10 min, a color change frompurple to orange-brown is observed. The solvent was removed undervacuum, the residue repeatedly washed with acetone or pentane (5 mL) anddried under vacuum for several hours. A red-purple microcrystallinesolid was obtained. Yield 627 mg (95%). ¹H NMR (CD₂Cl₂): δ 19.06 (d,³J_(HH)=10.5 Hz, Ru═CH), 8.11 (ddd, ³J_(HH) 10.5, ³J_(HH) cis=9.3,³J_(HH) trans=16.8 Hz, CH═CH₂), 6.25 (d, ³J_(HH) cis=9.3, H^(cis) ofCH═CH₂), 6.01 (d, ³J_(HH) trans=9.3, H^(trans) of CH═CH₂), 2.59-2.53,1.83-1.78, 1.52-1.47 and 1.25-1.21 (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂):δ 296.00 (t, J_(PC) 7.6 Hz. Ru═CH), 153.61 (s, CH═CH₂), 115.93 (s,CH═CH₂), 32.32 (pseudo-t, J_(app)=8.9 Hz, ipso-C of P(C₆H₁₁)₃), 29.82(s, m-C of P(C₆H₁₁)₃), 28.15 (pseudo-t, J_(app)=5.1 Hz, o-C ofP(C₆H₁₁)₃), 26.91 (s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 36.17 (s,PCy₃). Anal. Calcd. for C₃₈H₇₀Cl₂P₂Ru: C, 60.61; H, 9.13. Found: C,60.79; H, 9.30.

Synthesis of RuCl₂(═C═CH₂)(PCy₃)₂ (Complex 24)

In a procedure analogous to that used in synthesizing complex, 23,RuCl₂(═C═CH₂)(PCy₃)₂ was obtained as a tan microcrystalline solid, usingcomplex 10 (413 mg, 0.50 mmol) and 1,2-propadiene as starting materials.Yield 373 mg (98%). ¹H NMR (CD₂Cl₂): δ 3.63 (s, Ru═C═CH₂), 2.71-2.64,2.05-2.01, 1.81-1.53 and 1.32-1.23 (all m, P(C₆H₁₁)₃. ¹³C NMR (CD₂Cl₂):δ 327.41 (t, J_(PC)=17.2 Hz, Ru═C═CH₂), 99.34 (s, Ru═C═CH₂), 33.30(pseudo=t, J_(app)=8.9 Hz, ipso-C of P(C₆H₁₁)₃), 30.41 (s, m-C ofP(C₆H₁₁)₃), 28.32 (pseudo-t, J_(app)=5.0 Hz, o-C of P(C₆H₁₁)₃), 27.02(s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 35.36 (s, PCy₃). Anal. Calcd.for C₃₈H₆₈Cl₂P₂Ru: C, 60.14; H, 9.03. Found: C, 60.29; H, 8.91.

Synthesis of RuCl₂(═CHCH₂OAc)(PCy₃)₂ (Complex 25)

A solution of complex 10 (423 mg, 0.51 mmol) in CH₂Cl₂ (10 mL) wastreated with allyl acetate (555 μL, 5.10 mmol, 10 eq.) at −20° C. Whilethe solution warmed to RT within 10 min, a color change from purple toorange-brown was observed. The solvent was removed under vacuum, theresidue repeatedly washed with ice-cold methanol (5 mL portions) anddried under vacuum for several hours. A purple microcrystalline solid,RuCl₂ (═CHCH₂OAc)(PCy₃)₂, was obtained. Yield 342 mg (83%). ¹H NMR(CD₂Cl₂): δ 18.90 (t, ³J_(HH)=4.2 Hz, Ru═CH), 4.77 (d, ³J_(HH)=3.6 Hz,CH₂OAc), 2.09 (s, C(O)CH₃), 2.53-2.47, 1.81-1.70, 1.59-1.53 and1.26-1.22, (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂): δ 305.76 (t, J_(PC)=7.6Hz, Ru═C), 170.41 (s. C(O)CH₃), 83.19 (s, CH₂OAc), 32.59 (pseudo-t,J_(app)=8.6 Hz, ipso-C of P(C₆H₁₁)₃), 29.94 (s, m-C of P(C₆H₁₁)₃), 28.23(m, o-C of P(C₆H₁₁)₃), 26.91 (s, p-C of P(C₆H₁₁)₃), 20.91 (s, C(O)CH₃).³¹P NMR (CD₂ Cl₂): δ 36.66 (s, PCy₃). Anal. Calcd. for C₃₉H₇₂Cl₂O₂P₂Ru:C, 58.05; H, 8.99. Found: C, 58.13; H, 9.07.

Synthesis of RuCl₂(═CHCH₂C)(PCy₃)₂ (Complex 26)

In a procedure analogous to that used in synthesizing complex 25RuCl₂(═CHCH₂Cl)(PCy₃)₂ was obtained as a purple microcrystalline solidusing complex 10 (583 mg, 0.71 mmol) and allyl chloride (577 μL, 7.08mmol, 10 eq.) as starting materials. Yield 552 mg (80%). ¹H NMR(CD₂Cl₂): δ 18.74 (t, ³J_(HH)=4.5 Hz, Ru═CH), 4.43 (d, ³J_(HH)=4.8 Hz,CH₂Cl), 2.55-2.50, 1.81-1.70, 1.59-1.52 and 1.27-1.23 (all m,P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂): δ 303.00 (t, J_(PC)=7.8 Hz, Ru═C), 63.23(s, CH₂Cl), 32.05 (pseudo-t, J_(app)=8.8 Hz, ipso-C of P(C₆H₁₁)₃), 29.50(s, m-C of P(C₆H₁₁)₃), 27.81 (pseudo-t, J_(app)=5.2 Hz, o-C ofP(C₆H₁₁)₃), 26.56 (s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 37.36 (s,PCy₃). Anal. Calcd. for C₃₈H₆₉Cl₃P₂Ru: C, 57.39; H. 8.74. Found: C,57.55; H, 8.81.

Synthesis of RuCl₂(═CH(CH₂)₃OH)(PCy₃)₂ (Complex 27)

In a procedure analogous to that used in synthesizing complex 25,RuCl₂(═CH(CH₂)₃OH)(PCy₃)₂ was obtained as a purple microcrystallinesolid, using complex 10 (617 mg, 0.82 mmol) and 4-pentene-1-ol (823 μL,8.2 mmol, 10 eq.) as starting materials. Yield 459 mg (76%). ¹H NMR(CD₂Cl₂): δ 19.20 (t, ³J_(HH)=4.6 Hz, Ru═CH, 5.46(s(br.), OH),2.82-2.78, 2.06-2.01 and 1.62-1.58 (all m, CH₂CH₂CH₂OH), 2.55-2.51,1.84-1.81, 1.55-1.52 and 1.26-1.23 (all m, P(C₆H₁₁)₃). ¹³C NMR (CD₂Cl₂):δ 305.66 5, J_(PC)=7.3 Hz, Ru═C, 62.66 (s, CH₂OH), 33.01 and 30.08 (boths, CH₂CH₂) 32.32 (pseudo-t, J_(app)=8.5 Hz, ipso-C of P(C₆H₁₁)₃), 29.94(s, m-C of P(C₆H₁₁)₃), 28.28. (pseudo-t, J_(app)=5.3 Hz, o-C ofP(C₆H₁₁)₃), 26.91 (s, p-C of P(C₆H₁₁)₃). ³¹P NMR (CD₂Cl₂): δ 37.06 (s,PCy₃). Anal. Calcd. for C₄₀H₇₄Cl₂P₂ORu: C, 59.69; H, 9.27. Found: C,59.51; H. 9.09.

ROMP of Norbornene with Complexes 3-9 as Catalysts

Norbornene (59 mg, 0.63 mmol) was dissolved in CH₂Cl₂ (0.7 mL) andtreated with solutions of complexes 3-9 (6.25 μmol) in CH₂Cl₂ (0.3 mL)at RT. The reaction mixtures became viscous within 3-5 min and the colorchanged from brown-green to orange. The solutions were stirred at RT for1 hour, then exposed to air and treated with CH₂Cl₂ (2 mL) containingtraces of 2,6-di-tert-butyl-4-methylphenol and ethyl vinyl ether. Theresulting green solutions were stirred for 20 min and, after filtrationthrough short columns of silica gel, precipitated into vigorouslystirred methanol. White, tacky polymers were obtained that wereisolated, washed several times with methanol and dried under vacuum.Yields 95-99%, ≈90% trans, M_(n)=31.5-42.3 kg/mol, PDI (toluene):1.04-1.10.

Determination of Initiation and Propagation Rates in ROMP of Norbornenewith Complexes 3-9

1.25×10⁻⁵ mol of catalysts based on complexes 3-9 were weighed into NMRtubes and dissolved in benzene-d₆ (0.3 mL). Ferrocene stock solution inbenzene-d₆ (20 μL) was added as an internal standard. These mixtureswere treated with solutions of norbornene (23.5 mg, 0.25 mmol, 20 eq.)in benzene-d₆ (250 μL). A ¹H NMR-routine was started immediately, taking60 spectra within 40 min, then 200 spectra within 5 hour. The initiationrate constants (k_(i)) were determined by integration of H_(α)resonances of the initiating and propagating species. The propagationrate constants (k_(p)) were determined by monitoring the decrease ofmonomer concentration versus the internal standards. The results aregiven in Table III (above).

Reaction of Complex 10 with 3-methyl-1-butene and 3,3-dimethyl-1-butane

In individual NMR-tubes, a solution of complex 10 (5.0 mg, 6.1 μmol) inmethylene chloride-d₂ (0.5 mL) was treated with 10 equiv.3-methyl-1-butene and 3,3-dimethyl-1-butene (61.0 μmol), respectively.Whereas with the latter reactant, no reaction was observed within 12hours, a gradual (within 5 min) color change from red-purple to orangeindicates that complex 10 undergoes a reaction with 3-methyl-1-butene.Resonances in the ¹H NMR at δ 18.96 (d, ³J_(HH)=7.5 Hz, Ru═CHiPr), 2.27(m, CHCH₃) and 1.01 (d, ³J_(HH)=7.2 Hz, CHCH₃) may be attributed to theformation of RuCl₂ (═CH-i-Pr)(PCy₃)₂. However, the intensity of thesesignals did not increase in the course of the reaction, and after 10min, the corresponding resonances of complex 19 became dominant.

ROMP of cyclooctene and 1,5-cyclooctadiene with Complexes 10-16 asCatalysts

Complexes 10-16 (6.0 μmol) were individually dissolved in CH₂Cl₂ (0.5mL) and treated with neat cyclooctene or 1,5-cyclooctadiene (3.0 mmol,500 eq.) at RT. Accompanied by a color change from purple to orange, thereaction mixtures turned viscous within 3-5 min. The solutions werestirred at RT for 2.5 hour and, upon exposure to air, treated withCH₂Cl₂ (5 mL) containing traces of 2,6-di-tert-butyl-4-methylphenol andethyl vinyl ether. After 20 min, the viscous solutions were filteredthrough short columns of silica gel and precipitated into vigorouslystirred methanol. The resulting polymers were isolated, washed severaltimes with methanol and dried under vacuum. Cycloocteneamer (white tackypolymers): Yields 95-100%, M_(n=111)-211 kg/mol, PDI (toluene):1.51-1.63; polybutadiene: (white glue-like polymers): Yields 96-99%,56-68% cis, M_(n) 57.9-63.2 kg/mol, PDI (toluene): 1.56-1.67.

Determination of Initiation Rate Constants in Acyclic Metathesis of1-hexene with Complexes 10-16 as Catalysts

6.05 μmol of catalysts based on complexes 10-16 were placed into NMRtubes and dissolved in methylene chloride-d₂ (550 L). At 0° C., 1-hexene(22.7 μL, 0.18 mmol, 30 eq.) was added and a ¹H NMR-routine (at 0° C.)was started, taking 60 spectra within 40 min. The initiation rateconstants were determined by integration of the H_(α) resonances ofcomplexes 10-16 and 22. The results are given in Table IV (above).

X-ray Diffraction Study of RuCl₂(═CH-p-C₆H₄Cl)(PCy₃)₂ (Complex 15)

A maroon prism of complex 15 was obtained by slow diffusion of hexanesinto a concentrated solution of complex 15 in methylene chloride (0.5mL) within 24 hours. A crystal of the size 0.2 mm×0.3 mm×0.5 mm wasselected, oil-mounted on a glass fiber and transferred to a Siemens P4diffractometer equipped with a modified LT-1 low temperature system. Thedetermination of Laue symmetry, crystal class, unit cell parameters, andthe crystal's orientation matrix were carried out according to standardtechniques. Low temperature (158 K) intensity data were collected via a2θ-θ scan technique with Mo_(Kα) radiation.

All 7782 data were corrected for absorption and for Lorentz andpolarization effects and placed on an approximately absolute scale. Anyreflection with I(net)<0 was assigned the value |F₀|=0. There were nosystematic extinctions nor any diffraction symmetry other than theFriedel condition. Refinement of the model proved the centrosymmetrictriclinic space group P1 to be the correct choice.

All crystallographic calculations were carried out using either the UCLACrystallographic Computing Package or the SHELXTL PLUS program. Theanalytical scattering factors for neutral atoms were used throughout theanalysis; both the real (Δf′) and imaginary (iΔf″) components ofanomalous dispersion were included. The quantity minimized duringleast-squares analysis was σx(|F₀|−|F_(c)|² wherew⁻¹=σ²(|F₀|)+0.0002(|F₀|)². The structure was solved by direct methods(SHELXTL) and refined by full-matrix least-squares techniques. Hydrogenatoms were located from a difference-Fourier map and included withisotropic temperature parameters. Refinement of the model led toconvergence with R_(F)=3.5%, R_(wF)=3.6% and GOF=1.42 for 726 variablesrefined against those 6411 data with |F₀|>3.0σ(|F₀|)). A finaldifference-Fourier map yielded ρmax=0.52 eÅ⁻³.

What is claimed is:
 1. A process for synthesizing telechelic polymers bymetathesis polymerization, comprising contacting a cyclic olefin with acompound of the formula:

in the presence of an α,ω-difunctional olefin, wherein: M is selectedfrom the group consisting of Os and Ru; R¹ is hydrogen; R is selectedfrom the group consisting of hydrogen, substituted or unsubstitutedalkyl, and substituted or unsubstituted aryl; X and X¹ are independentlyselected from any anionic ligand; L and L¹ is selected from any neutralelectron donor.
 2. A process for synthesizing olefins by crossmetathesis, comprising contacting a first acyclic olefin with a compoundof the formula:

in the presence of a second acyclic olefin, wherein: M is selected fromthe group consisting of Os and Ru; R¹ is hydrogen; R is selected fromthe group consisting of hydrogen, substituted or unsubstituted alkyl,and substituted or unsubstituted aryl; X and X¹ are independentlyselected from any anionic ligand; L and L¹ are selected from any neutralelectron donor.
 3. The process of claim 1, wherein the substituted alkylincludes one or more moieties selected from the group consisting ofaryl, alcohol, thiol, ketone, aldehyde, ester, ether, amine, imine,amide, nitro, carboxylic acid, disulfide, carbonate, isocyanate,carbodiimide, carboalkoxy, and halogen.
 4. The process of claim 1,wherein the substituted aryl includes one or more moieties selected fromthe group consisting of alkyl, aryl, alcohol, thiol, ketone, aldehyde,ester, ether, amine, imine, amide, nitro, carboxylic acid, disulfide,carbonate, isocyanate, carbodiimide, carboalkoxy, and halogen.
 5. Theprocess of claim 1, wherein R is selected from the group consisting of(a) hydrogen; (b) C₁-C₂₀ alkyl; (c) aryl; (d) C₁-C₂₀ alkyl substitutedwith one or more moieties selected from the group consisting of aryl,halide, hydroxy, C₁-C₂₀ alkoxy, and C₂-C₂₀ alkoxycarbonyl; and (e) arylsubstituted with one or more moieties selected from the group consistingof C₁-C₂₀ alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, and halide.6. The process of claim 5, wherein R is phenyl or phenyl substitutedwith a moiety selected from the group consisting of chloride, bromide,iodide, fluoride, —NO₂, —NMe₂, methoxy, and methyl.
 7. The process ofclaim 5, wherein R is selected from the group consisting of hydrogen,methyl, ethyl, n-butyl, iso-propyl, —CH₂Cl, —CH₂CH₂CH₂OH, and —CH₂OAc.8. The process of claim 2, wherein the substituted alkyl includes one ormore moieties selected from the group consisting of aryl, alcohol,thiol, ketone, aldehyde, ester, ether, amine, imine, amide, nitro,carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide,carboalkoxy, and halogen.
 9. The process of claim 2, wherein thesubstituted aryl includes one or more moieties selected from the groupconsisting of alkyl, aryl, alcohol, thiol, ketone, aldehyde, ester,ether, amine, imine, amide, nitro, carboxylic acid, disulfide,carbonate, isocyanate, carbodiimide, carboalkoxy, and halogen.
 10. Theprocess of claim 2, wherein R is selected from the group consisting of(a) hydrogen; (b) C₁-C₂₀ alkyl; (c) aryl; (d) C₁-C₂₀ alkyl substitutedwith one or more moieties selected from the group consisting of aryl,halide, hydroxy, C₁-C₂₀ alkoxy, and C₂-C₂₀ alkoxycarbonyl; and (e) arylsubstituted with one or more moieties selected from the group consistingof C₁-C₂₀ alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, and halide.11. The process of claim 10, wherein R is phenyl or phenyl substitutedwith a moiety selected from the group consisting of chloride, bromide,iodide, fluoride, —NO₂, —NMe₂, methoxy, and methyl.
 12. The process ofclaim 10, wherein R is selected from the group consisting of hydrogen,methyl, ethyl, n-butyl, iso-propyl, —CH₂Cl, —CH₂CH₂CH₂OH, and —CH₂OAc.13. A compound of formula:

wherein: M is selected from the group consisting of Os and Ru; R¹ ishydrogen; R is a substituted or unsubstituted C₂-C₂₀ alkenyl group; withthe proviso that when R is a C₂ alkenyl group, it is not substitutedwith both a methyl and a phenyl group, disubstituted with phenyl groups,or disubstituted with methyl groups; X and X¹ are independently selectedfrom any anionic ligand; and L and L′ are independently selected fromany neutral electron donor.
 14. The compound of claim 13, wherein thesubstituted alkenyl includes one or more moieties selected from thegroup consisting of aryl, alcohol, thiol, ketone, aldehyde, ester,ether, amine, imine, amide, nitro, carboxylic acid, disulfide,carbonate, isocyanate, carbodiimide, carboalkoxy, and halogen.
 15. Thecompound of claim 13, wherein the substituted alkenyl includes one ormore moieties selected from the group consisting of C₁-C₂₀ alkyl, aryl,alcohol, thiol, ketone, aldehyde, ester, ether, amine, imine, amide,nitro, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide,carboalkoxy, halogen, and aryl substituted with one or more moietiesselected from the group consisting of C₁-C₂₀ alkyl, aryl, hydroxyl,C₁-C₅ alkoxy, amino, nitro, and halide.
 16. The compound of claim 13,wherein the substituted alkenyl includes one or more moieties selectedfrom the group consisting of N-Ts, N-Fmoc, N-Boc, COOEt, OSiEt₃, phenyl,SiMe₂, OBn, OR, NCOOtBu, and SO₂Ph.
 17. The compound of claim 13,wherein the substitution of the substituted alkenyl takes place in thebackbone of the alkenyl group.
 18. The compound of claim 13, wherein thesubstitution of the substituted alkenyl takes place outside the backboneof the alkenyl group.
 19. The compound of claim 13, wherein R is asubstituted or unsubstituted C₃-C₂₀ alkenyl group.
 20. The compound ofclaim 13, wherein R is an unsubstituted C₂ alkenyl group, or a C₂alkenyl group substituted with one or more moieties selected from thegroup consisting of aryl, alcohol, thiol, ketone, aldehyde, ester,ether, amine, imine, amide, nitro, carboxylic acid, disulfide,carbonate, isocyanate, carbodiimide, carboalkoxy, and halogen.